March 19, 2025 • 39 mins
What is this mysterious technology, and how is it going to affect our lives? Jorge talks to a Quantum scientist and visits their lab to see and hear these machines in action.
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Speaker 1 (00:01):
Hey, welcome to Sign Stuff, a production of iHeartRadio. My
name is Jorge cham and to the end of the program,
we are talking about a technology that may potentially impact
the life of every single human on Earth. It might
change how we protect data and come up with passwords,
it might help us make new and exciting materials, and
it might render cryptocurrencies like bitcoin and dotgecoin totally useless.
(00:26):
I'm talking about quantum computers. What are they, how do
they work? And most exciting is that we're going to
get to visit one of them and actually hear it
in action. So power up your curiosity, log in, and
let's answer the question how do quantum computers work? Hey? Everyone? Okay,
(00:48):
so when I started this episode, I was both terrified
and excited. Terrified because explaining anything with the word quantum
is really hard, but excited because I had heard that
a friend of mine was making quantum computers just ten
minutes from my house, and this was a great excuse
for me to go take a look at them. So
we're going to go see these quantum computers in person
(01:10):
at the end of the episode, but before that, I
wanted to make sure that I understood what they were
how they work, and also what they're potentially going to
be used for. So this episode is split into three parts.
What is a quantum computer and how does it work?
What are quantum computers for? And then we're going to
go see the quantum computers and we're going to talk
(01:30):
about how they're made and why they're so hard to
get them to work. Our guide through all of this
is going to be my friend who's making the quantum computers,
Professor Oscar Pater. He's a professor of physics and applied
physics at Caltech and he's the head of quantum hardware
for Amazon. He does research on nanophotonics, quantum optics, and
of course quantum computers. Here's my visit to Oscar Painter's lab.
Speaker 2 (02:00):
Ah, hey, Oscar, how are you good to see you
after so many years.
Speaker 1 (02:04):
Yeah, it's been a while. Huh yeah, well thanks so
much for talking with me.
Speaker 3 (02:07):
Yeah, it's been a while. Happy to try to fill
you in on some of the things we've been doing
in the areas of quantic computing.
Speaker 1 (02:13):
Okay, so the first thing I wanted to talk to
him about was just what does the word quantum mean?
Because I feel like we're going to need that to
understand what a quantum computer is. Now, the word quantum
is the word we used to describe how things behave
at the level of atoms and the tiny little particles
that make up the atoms. So in our everyday lives,
(02:35):
we're used to things being solid and us being able
to hold them, like, for example, if you take a
piece of wood or a ball. But if you take
that piece of wood or ball and you chop it up,
and you keep chopping it up, you get down to atoms,
and then you'll notice that those atoms don't behave in
the same way that a piece of wood or a
ball do. Here's how Oscar explains it.
Speaker 3 (02:55):
It turns out that down to the microscopic scale, so
not our everyday scale of things, the laws of physics
that dominate in that regime is quantum mechanics, and quantum
mechanics is a theory that has some strange attributes that
we don't experience every day. For example, it postulates that
things can be in superposition, so you can have objects
being in sort of what we think of as two
(03:17):
distinct realities at the same time. Imagine having a particle
in one position and another position simultaneously. That seems very
odd to us, but in quantum mechanics it's very natural.
Speaker 1 (03:28):
Like, for example, I grabbed this piece of wood in
front of me, and it's a piece of wood. It's
not two things at the same time. Right, It's in
one location.
Speaker 3 (03:35):
Right, it's sitting there. It's firmly right in front of you.
Speaker 1 (03:37):
Right. If I had an atom in front of me
or an electron, it wouldn't exactly.
Speaker 3 (03:42):
You would find that if you repeated the measurement or
finding its position multiple times, you might find that, Oh,
I get this weird outcome that sometimes I measure it here,
sometimes I measure it there. And that's because it's actually
in many places at once, all right, And that's fundamental
to the description of quantum mechanics. The way I like
to think about quantum mechanics is really as waves and amplitudes.
(04:03):
So think about you're at a pond and you throw
a rock in a pond, and you see this ripple
of the rock. Right, That's how I think about, Like
the rocks are sort of the particles, and these wave
phenomena are sort of the actual physical quantum mechanical description
of that particle.
Speaker 1 (04:18):
Like the particle the thing, the atom or the electron.
It's not the rock you throw into the pond, no,
but it's actually the ripple of the ripple.
Speaker 3 (04:25):
Yeah, that's right, it's this wave. So I may have
started with something that was very local, like that rock,
but then it becomes very quickly it sort of propagates
out and is actually better described as this wave on
the pond.
Speaker 1 (04:36):
Because like a ripple and a wave in a pond
like that, it's kind of in a lot of places
at the same.
Speaker 3 (04:40):
Exactly, that's right. And then the interference is important to understand.
If I throw two rocks in the pond, then I
see the sort of interference of the ripple patterns coming
from each rock that blashed in the pond.
Speaker 1 (04:51):
Right, Like each ripple starts at simple, but then they
start to mix together and form this complex pattern on
the surface of the pod.
Speaker 3 (05:00):
Exactly, like how do they evolve in time?
Speaker 1 (05:03):
Okay, so when you get down to the level of atoms,
things behave really strangely. Scientists think of things at that
level not as little tiny balls, but as waves or
ripples of energy, like the ripples in a pond. Now
you may think, wait a minute, if things are kind
of wavy and strange at the level of atoms. Why
isn't it that way when you get to big stuff
(05:25):
like a piece of wood or a ball, And the
answer is that they are that way. There's just a
lot of atoms in a piece of wood, and from
a distance, it gives you the impression that it's solid.
It's sort of like how some clouds from afar they
might look solid once you get up close to them,
they're actually kind of fuzzy and wispy, and all the
(05:46):
water droplets are moving around. So that's quantum. Now. A
quantum computer is what happens when you make a regular computer,
but you make the circuits out of individual atoms or
particles like electrons.
Speaker 3 (06:00):
Classical computers are formed from things that are very very
classical in nature.
Speaker 1 (06:04):
And they uperate kind of on hard switches.
Speaker 3 (06:07):
Yeah, like, yeah, that's right, the transistors on your phone,
And that's what we call these types of elements. The
transistors are used to store information or perform calculations, and
the transistors are really set by a bunch of electrons
in part of the circuit. And usually you're talking about
quite a few electrons.
Speaker 1 (06:21):
Because regular transistors are huge. They're bigger than an atom.
Speaker 3 (06:25):
Yes, exactly, that's physically what's going on in your phone.
And what I'm telling you is that the way to
think about it is in the quantum case, I just
have one electron.
Speaker 1 (06:34):
Like the circuits are made out of individual electrons.
Speaker 3 (06:37):
Yeah, atoms is exactly what you're doing. Or a quantum
particle doesn't have to be electrons, can be other particles.
That was the sort of very early idea from people
like FIM and others back in the nineteen eighties is
if you're going to do this, and you better make
them out of quantum mechanical objects to begin with.
Speaker 1 (06:53):
Okay, So if you make a computer where the circuits
are made of individual quantum objects like atoms or electrons,
then you get a quantum computer. And what that does
is that it makes their calculations also quantum mechanical. And
this is where the concept of a cubit comes in.
It's like a regular bit in your computer, and a
(07:13):
bit is like a one or zero, but a cubit
is a quantum mechanical one or zero.
Speaker 3 (07:20):
Classical computers are formed from digital bits and they go
between one and zero. A quantum computer doesn't have these
hard zero one states. It has every possibility in between.
So imagine if we have these two states zero in one.
I told you that a quantum system can be in
two different states at once, right, So it can be
in zero and one at the same time, and I
(07:42):
can have a different weight of zero or one at
the same time. It could be ten percent zero, ninety
percent one.
Speaker 1 (07:48):
It's like a shade of gray.
Speaker 3 (07:49):
Yeah, And so you have all those possibilities in between.
It can be zero or one or anything in between.
Speaker 1 (07:55):
It can be black, white, dark, gray, light.
Speaker 3 (07:58):
Gray, exactly, So it has all those shape in between.
You can take zero with some fraction and add it
to one with any other fraction. You can have any
combination of that.
Speaker 1 (08:07):
So on a regular computer, if you multiply two bits together,
it's like you're multiplying two fixed numbers together, like three
times four. But in a quantum computer, when you multiply
two cubits together, it's like you're multiplying two things that
can be lots of numbers at the same time. So,
for example, it's like you're multiplying every number from zero
(08:28):
to one hundred times every number from zero to one thousand,
all at the same time in one operation. That's what
makes quantum computers unique. They take this weirdness of the
quantum world and then let's you do math with it. Now, Actually,
it's not doing all of those multiplications or calculations at
the same time. It's more like how Oscar described it earlier.
(08:49):
If you drop two rocks in a pond, you see
the two ripples spread out and mix together to form
a complex ripple pattern. That's more of the picture of
what a quantum comp does. It doesn't do calculations with
hard numbers. It does calculations with the ripples and patterns
of quantum numbers. Of course, my next question for Oscar
(09:10):
was what is that good for? Why would you want
to do math this way? When we come back, I'm
going to ask Oscar what quantum computers are for, and
then at the end we're going to go check out
the ones he's built. You're listening to sign stuff. Welcome back. Okay,
(09:35):
to recap, we learned that a quantum computer is a
regular computer whose circuits are made with individual atoms or
small particles like electrons, and by doing that you can
do quantum calculations. That is, you can do math, but
with numbers that are actually lots of different numbers at
the same time. So now the question is, why would
you want to do that? What are quantum computers? Four?
(09:58):
Here's more of my conversation, but quantum physicist Oscar Painter.
Let's say it's a few years into the future and
we have quantum computers, yes, in our phones, like I
have one in my podget Okay, what can I do
with it? And how is my life different?
Speaker 3 (10:13):
I think that's a very unlikely scenario.
Speaker 1 (10:16):
Okay.
Speaker 2 (10:17):
I think that's the wrong way.
Speaker 3 (10:19):
To think about how quantic computers might change our lives,
at least as far as I can project into the future. Okay,
I think the best way to think about a quantic
computer as we envision it right now is that it
will be more.
Speaker 2 (10:33):
Like a supercomputer.
Speaker 3 (10:34):
So a supercomputer is just a very large computer that
can perform calculations beyond what our desktop, our personal computers
can do. And these are usually very large, almost building
scale computers and computer clusters that have many, many different
processing units that are all integrated together, and through that
scale you can perform a huge number of computations per
(10:55):
second and therefore compute some of the hardest problems.
Speaker 2 (10:58):
That are out there.
Speaker 3 (10:58):
A lot of them are used for chemistry problems. They're
used to study particle physics, so fundamental physics, trying to
understand models of quantum particles that are beyond the current
standard model. They're used to compute the properties of materials,
climate modeling, and things like that.
Speaker 1 (11:14):
So usually science and tech, yeahs, And.
Speaker 3 (11:17):
There's always this competition between different nations who has the
fastest or the biggest supercomputer.
Speaker 1 (11:22):
I see, So you envision quantum computers will be sort
of like a specialized version of computer.
Speaker 3 (11:28):
It's going to be some very special type of supercomputer
that can solve specific problems that quantum computers will be
very effective at that we can't do today on classic computers,
no matter how much we scale them up. And the
key is it's not just a faster supercomputer. It performs
calculations in a fundamentally different way, and therefore it can
tackle problems that are possibly outside of the reach of
(11:49):
these conventional classical supercomputers.
Speaker 1 (11:52):
What do you mean? Out of the reach meaning that.
Speaker 3 (11:54):
No matter how fast they get or how big they get,
they'll never be able to compute some of these problems,
never or take an infinite exactly, it's just the scaling
is so bad for these problems, you would take way
too long and require way too large on machine. So,
no matter how hard we work on our current computing technology,
it has limits and it's known and you can prove
(12:16):
it for certain problems, and quantic computers when they looked
at theoretically these same problems, they realize that the same
restrictions or limitations for quantic computers are not there. There's
examples where we believe and strongly believe that certain mathematical
problems that are important are really really hard to perform
(12:38):
and can't be solved using classical means, no matter how
much we improve the technology.
Speaker 1 (12:42):
No matter if I have a building full of supercomputers,
yeah exactly, you'll never be able.
Speaker 3 (12:46):
To just fill the world with them. You still won't
be able to do it. Yet a quantic computer can
solve it pretty efficiently.
Speaker 1 (12:53):
Well. Step me through some of these problems.
Speaker 3 (12:55):
Like so the example that everyone points to, and it
is pretty amazing that people found this, But there's this
mathematical problem. It just happens to be very applicable to
our safety or security of our data. So it turns
out that most of the security of all of the
data that you hold, all the data that banks or
various institutions around the world want to be safe and protected,
(13:18):
they typically encrypt it. And those encryption techniques that have
been used were what are called RSA encryption, where you
want to take a large number and understand what its
prime factors are.
Speaker 1 (13:29):
Okay, so the first big thing that quantum computers can
be useful, the one that got people really excited about
them in the nineties, is in breaking password encryption. So
whenever you enter your password on a website or when
you download your bank statement, that information is encrypted or
scrambled so that if anyone happens to catch that information,
(13:51):
they can't tell what it says. And the whole scheme
is based on the idea that if I gave you
a really large number, it's really hard to find what
its prime factors are. Here's how Oscar explains it, but
just to give you a quick heads up, a prime
number is a number that can't be divided except by
itself or by one. So, for example, thirteen is a
(14:14):
prime number because you can't fight thirteen by anything except
thirteen and one, And the same goes for seventeen nineteen
twenty three and so on. Anyways, here's Oscar explaining it.
Speaker 3 (14:27):
So I give you a number and I say, tell
me what the prime factors are, and you have to
break it down to its prime factors. So you know,
a simple one is, you know, like two, it's just
one times two, one and two. Those are the two
prime factors, right. But it gets harder as these numbers
get bigger.
Speaker 1 (14:41):
If I tell you one millions be round there and
forty three.
Speaker 3 (14:44):
Yeah, seventeen, very hard to actually answer what those what
the prime factors are. But if I give you the
prime factors, you can multiply them together and very quickly
get the answer to what that larger number is.
Speaker 2 (14:56):
Right.
Speaker 3 (14:57):
And so if you know the prime factors, I can
give you what they multiply to.
Speaker 2 (15:00):
But if you give me.
Speaker 3 (15:01):
The number that they multiply to without then I have
a very hard time finding out what the prime factors are.
Speaker 1 (15:06):
Because you'd have to get kind of have to guess.
Speaker 3 (15:09):
Well, you know, there's mathematical techniques to try to find these,
but they're very inefficient.
Speaker 2 (15:14):
And so it turns.
Speaker 3 (15:15):
Out that most of the security of the way we
encrypt information is based upon that asymmetry. And how hard
the problem is.
Speaker 1 (15:23):
So, now, let's say somebody has a quantum computer.
Speaker 3 (15:25):
Right, then they can find those prime factors and they
can now decrypt all that information.
Speaker 1 (15:32):
They can just grab it from the air, yeah, and
be like, oh, I know.
Speaker 3 (15:35):
And yeah, I can find the prime factors and then
I can use that to decrypt the information.
Speaker 1 (15:42):
That would be easy for a quantum computer, and you
just press a button and will tell you, oh, this
is an oscar or his secret decoder.
Speaker 3 (15:48):
Yeah, exactly, So that would you know. That obviously concerned
a lot of people when that algorithm was developed.
Speaker 1 (15:58):
Okay, this gets a little bit heavy into encryption and
quantum algorithms, but the main point is that most of
the security of our passwords and our sensitive information, and
also the encryption of things like bitcoin and all those cryptocurrencies,
they all depend on this one math problem which is
really hard for regular computers even supercomputers to solve. And
(16:20):
that is a problem of finding the two prime numbers
that multiply to get a really large number. But then
in nineteen ninety five, a computer scientist named Peter Shore
publish the paper titled Polynomial time Algorithms for prime factorization
of discrete logarithms. On a quantum computer, which essentially showed
that if you have a quantum computer, you can solve
(16:40):
this problem in a short amount of time. And this
is probably the main reason that people have been rushing
to make quantum computers since then, because imagine if everyone
in the world, people, companies, countries are all protecting their
secrets using the same trick, but you had a special
quantum computer that could break that trick, you could rule
the world. Now, the details of how Peter Shore's algorithm
(17:03):
works are a little complicated to explain here, but the
essence of it is that you're using the ripples on
a pawn nature of quantum numbers on a quantum computer
to basically try out every possible combination for how to
break your secret encryption, and you use some clever math
tricks so that these ripples combine and mix together until
(17:23):
the right answer pops out. So that is the main
reason that people are excited about quantum computers. But there
are other reasons and other possible applications, So here's Oscar
telling me about them.
Speaker 3 (17:37):
Another example is maybe more natural to think about, and
this is where quantum computers were first proposed. It to
be interesting or useful, and that is the simulation of
nature itself. Nature as we know it is not classical.
If you peel the layers of the onion enough and
you get down to the core, right to the atomic scale,
it turns out that the laws of physics that dominates
(17:59):
quantum mechanics, okay, like the actual mathematics of that, when
you describe it, when you have many particles, it quickly
becomes something that you can't simulate with a classical computer.
So all those interference of all the particles and keeping
track of all of that. A classical computer, if you
try to simulate that, you quickly run out of steam
and it becomes an exponentially hard problem. And so you know,
(18:21):
a classical computer is just ill suited.
Speaker 2 (18:23):
To doing that.
Speaker 3 (18:24):
But a quantum computer that's made out of the same
those sort of particles that can do with that interference naturally,
you know, has a natural advantage in terms of using
it to simulate the natural world at its quantum mechanical core.
Speaker 1 (18:35):
Why would I want to do that?
Speaker 3 (18:36):
Yeah, So that's the questions like, okay, so that's great,
but why would I want to do that other than
maybe I want to understand physics better? Well, this idea
that I want to understand how material behaves is a
very good example. If I'm building an electrical circuit, or
I'm building a new battery, or I'm building a different
energy process inside of a material or energy storage device.
A lot of times that depends on what the electrons
(18:57):
are doing. If I want to understand or something unique
when I describe them quantum mechanically, maybe there's special properties
I'm just totally blind to. So if I wanted to
make a better superconnecting material, something that can carry electricity
with no resistance, right, maybe we can have magnetically livitated trains.
Maybe you can have you know, really efficient electrical circuits
(19:18):
that don't dissipate any energy.
Speaker 2 (19:19):
All of these things.
Speaker 3 (19:20):
Then I would have to use a quantum computer to
model that behavior.
Speaker 1 (19:23):
And you said there's some maybe potential applications in chemistry
and biology.
Speaker 3 (19:27):
Yeah, you know, if I think about what is going
on when I have a chemical reaction, usually it comes
down to the electrons, and I need to understand what
they're doing in order to understand, you know, whether this
chemical reaction is going to be efficient or not, or
if I want to describe it with chemical accuracy, so
I can use it to, you know, do some sort
of industrial chemical process. The biological application. It's like, if
(19:48):
I want to know how molecules are biologically relevant molecules
lined together, then potentially I need to know more information
about the electronic behavior in these molecules. If I wanted
to do that without having approximation or much higher accuracy
than a quantum computer would be potentially more capable.
Speaker 1 (20:04):
There I we might be able to predict better how
a vaccine will work, or whether a certain chemical introduce
in your body will.
Speaker 3 (20:11):
Right now, we don't have that sort of level of specificity.
I mean, we'd love too. People are proposing techniques, but
that's the right idea, by the devil's in the details.
And you know, you have people saying, well, look, you know,
I think even today there's I won't call them skeptics,
but there's a lot of people that are saying, well,
I can keep improving my classical algorithms, and whether you
can really gain advantage from the quantum simulations is a
(20:34):
it's a practical question, and maybe we don't have as
clear an example or as clear a win when it
comes to how quantum computers will will do better, or
be more efficient, or be able to do the calculations
fast or even do them ones that the classical computers
can't do. But I think there's definitely something there. It's
just that we still have to work on a quantum algorithms.
It's not as clear cut, I would say.
Speaker 1 (20:55):
So those are the two main applications or uses for
planted computers. One is in breaking encryption using a special
algorithm called phase estimation that only works in a quantum computer,
and the other is to simulate nature, because nature is,
after all quantum at its core, and so scientists think
that quantum computers will let us better simulate how atoms
(21:18):
and electrons interact so that we can design better materials,
better semiconductors, and maybe better medicines. Now, I said so far,
because this is all still very new, and there might
be other classes of problems like the encryption problem where
quantum computers are just fundamentally and exponentially better at solving,
(21:39):
but nobody knows for sure. Of course, it's all hinges
on whether or not we can actually make quantum computers
at the level that they would actually be useful and
most important, reliable. So now we're going to go actually
see these quantum computers that Oscar is building, and he's
going to tell us why they're hard to make and
why they're so prone to making errors. But first, let's
(22:00):
take a quick break. You're listening to science stuff and
we're back. Well I heard you have a quantum computer
in your basement.
Speaker 3 (22:16):
Well not in my basement, but in my my laboratory. Yeah, here,
can we go see it?
Speaker 2 (22:21):
We can?
Speaker 1 (22:22):
Okay, yeah, let's get see it.
Speaker 2 (22:23):
Okay, you want to do that?
Speaker 1 (22:24):
Okay, so where are we going?
Speaker 2 (22:28):
Just the next door.
Speaker 3 (22:29):
We don't actually even have to go down into.
Speaker 2 (22:31):
The basement, into the basement, no.
Speaker 1 (22:34):
Basement sound and more.
Speaker 2 (22:36):
Yeah, i'd scientists exactly.
Speaker 3 (22:37):
So let's all these labs have different variants of quantic
computers that we're testing. Multiple quantum computers here, yeah, yeah,
not just one. So there's small scale quantum computers, but
the largest ones are you know, ones at at Amazon
or Google or IBM or you know some of the
(22:58):
other startup companies. These get to be maybe a factor
of ten times larger than the ones I'll show you. Okay, okay,
so this gives you an idea. All of these control electronics,
right is to use to control about twenty of these
quantum bits.
Speaker 1 (23:12):
There's twenty quantum meaning twenty particle. A machine made up
of twenty quantum particles.
Speaker 3 (23:18):
Corract right, which we are manipulating as quantum bits, and
that circuit lives down inside of this special refrigerator.
Speaker 1 (23:26):
Okay, So if you've ever seen, or if you google
a picture of a quantum computer, most likely what you
see is something that looks like an upside down metal
wedding cake with circular tears or platforms that get smaller
and smaller as they hang down from the ceiling. That
is basically a super intense refrigerator. The whole purpose of
(23:49):
it is to get the tip of that upside down
cake really really really cold.
Speaker 3 (23:56):
And this refrigerator is under vacuum, under high vacuum. It's
a temperature which is about ten million degrees above absolute zero.
Speaker 2 (24:03):
Ten degrees.
Speaker 3 (24:04):
So to give you an idea, So if I go
to the deepest part of space, it's a few degrees calvin,
a few degrees above that food and zero, the coldest
darkest parts of outer space or that universe. Yeah, but
this thing's about thirty times colder than that.
Speaker 1 (24:18):
Even WHOA So would you say that some of the
cold this places in the whole universe.
Speaker 3 (24:25):
I mean no, I mean you can get there's people
that do this for a living that make really cold things.
Speaker 2 (24:29):
But this is among the very very coldest things. Okay, yeah,
but this is extremely cold.
Speaker 1 (24:34):
What does it need to be cold?
Speaker 3 (24:36):
Because even the lights, even if we turned all the
lights off, even just the fact that the room's hot, it's.
Speaker 2 (24:42):
Room temperature, but it radiates.
Speaker 3 (24:44):
Radiation, and that radiation would completely destroy the information in
the corner bit.
Speaker 2 (24:49):
I see. We have to get it really dark.
Speaker 3 (24:51):
We have to make sure that there's not any of
this thermal energy that's making it into the circuit, otherwise
it'll destroy the manipulation of those quantum parties. And so
it has to be as isolated as we can from
the environment. We would ideally seal it off from everything,
so it would be like zero temperature and there would
be nothing coming in other than what we want to
send to it to control it.
Speaker 2 (25:10):
And then you can see there's all of these cables,
uh huh. Each of these feeds.
Speaker 3 (25:14):
Into a microwave cable that could use to control individual
quantum bits or quantum particles on the circuit.
Speaker 1 (25:22):
So what I'm looking at is a room full of
electronics and cables, and in the center is a massive
structure with two suspended eye beams, and hanging from those
beams is the upside down wedding cake I mentioned before,
which in this case is sealed inside a really thick
metal cylinder, and inside that cylinder at the very tip
(25:45):
of the wedding cake cool to almost the coldest anything
can be in the whole universe. Is a little chip?
Good a quantum computer?
Speaker 2 (25:54):
Well?
Speaker 1 (25:55):
What's in there? So describe me what's inside the core
of it? Is it like a little chip? Yeah?
Speaker 2 (25:59):
Like love.
Speaker 3 (26:00):
It's what's called a superconnecting quantum circuit. So it uses
little metal traces on a silicon wafer that we pattern
on the surface, and when you get them cold enough,
they become super connecting, which means they can carry electrical currents.
Speaker 2 (26:12):
Without any energy dissipation.
Speaker 3 (26:14):
Okay, And it turns out that you can form these
sort of quantum particles like these atoms, where the current
is circulating in a clockwise way inside of a little
tiny ring, or it's circulating counterclockwise, and the clockwise could
be zero, when the counterclockwise could be one, and you
can get in any superposition of these two circulation patterns,
and I can use then I can manipulate what the
(26:35):
superposition is, and I can have interact with other circulating currents.
Speaker 2 (26:40):
To the things in our circuit.
Speaker 3 (26:43):
There are a few hundred microns in size, so they
might be a few times the human hair diameter, so
they're pretty big relative to conventional transistors. It's made out
of many atoms, but it behaves like a single atom.
Speaker 2 (26:55):
Okay, yeah, the way to think about it.
Speaker 1 (26:57):
So there's like a little array of these things, a.
Speaker 3 (26:59):
Little array of these things on the surface of a microchip,
and then each of them we can control the current flow.
So what are called single cubit gates. We bring them
together and then let them interact them bring them apart.
So I need to be able to manipulate the single particle,
put it in any sort of superposition I want.
Speaker 2 (27:13):
And then you have to read out the state of
these cubits too.
Speaker 3 (27:15):
You have to know after I do my computation, are
you in state zero or state one? All right, I
have to ask that question for all my cubits, and
that will give me the answer.
Speaker 1 (27:23):
I see what is that hearing?
Speaker 3 (27:25):
So this is called the pulse tube cooler sownders sounds
like if you were ever a kid growing up in
the eighties and you watch Battlestar Galactica or the Cylons
and Battlestar Galactica, they do they walk, and they would
have this flashing light and they'd have this sort of
sound coming from them.
Speaker 2 (27:39):
This is a similar sort of sound.
Speaker 3 (27:40):
This is a pulse tube cooler and it's shooting a
slug of helium gas onto a cold plate and then
in doing so, when it expands, it can cause cooling.
It's analogous to what you do with the regular refrigerator.
That's the first stage of cooling, though that only gets
you down to maybe a tenth of the temperature of
the room. And then if I want to go even
cooler down and by another factor of ten or one hundred,
(28:01):
then you have to use a recirculating gas.
Speaker 2 (28:03):
In this case, it's a dilution fridge that takes mixtures
of isotopes.
Speaker 3 (28:07):
Of helium helium three and helium four, and when they mix,
there's an entropy of reaction and that's what gets you
down to this lowest temperatures I mentioned.
Speaker 1 (28:14):
So it's several stages. Something like take a fridge put
it inside of another fridge.
Speaker 3 (28:19):
So there's actually like sort of three or four stages
of if you're inside of a fridge and you have
instead of the fridge, the one fridge is too hot
for the other fridge, so we have to isolate them,
and then we have to do that for every successive stage.
Speaker 1 (28:32):
It's like, if I take my freezer and I put
it inside of like a restaurant freezer, just be colder.
Speaker 2 (28:37):
Yeah, okay, exactly, I keep doing that. I add, you know, another.
Speaker 1 (28:39):
Way, the fridge inside of my fridge have a restaurant freezer.
Speaker 3 (28:42):
And I keep you know, each of them has the
ability to get colder and colder. Yeah, So you have
to do it in stages. Otherwise, if you try to
do a direct shot, it's too much of a thermal
load on the system.
Speaker 1 (28:50):
I see. So that's a quantum computer in action. Most
of what you see when you look at a picture
of a quantum computer, it's all the machinery needed to
keep the actual circuit in a near perfect vacuum and
as cold as possible, and all of that is to
completely isolate the quantum computer from the outside world. We'll
(29:11):
get to why you need to do that with a
quantum computer. But first I was curious how much a
quantum computer like this costs. Here's what oscars it. Well,
this is definitely much bigger than my phone.
Speaker 2 (29:23):
Yes, exactly.
Speaker 3 (29:24):
That's why I was saying, you're probably not going to
carry one of these things around.
Speaker 1 (29:27):
How much is this something like this if I wanted
to build one in my garage?
Speaker 3 (29:31):
Okay, Well, you know there's always a big difference between
science money and money that you know, when you're talking
about conservative products that have large volumes. I remember the
first time we purchased a big piece of equipment from
my lab when I was the first a faculty member.
Speaker 2 (29:43):
It was about the same.
Speaker 3 (29:45):
It was about smaller than this thing, so smaller than
a few cubic feet, but it was more expensive than
my house when I bought it.
Speaker 2 (29:52):
So there's a big difference. Cot So just keep that
in mind.
Speaker 3 (29:55):
But one of these systems today, because it's very specialized,
probably costs about a.
Speaker 2 (29:59):
Million dollars set up.
Speaker 3 (30:00):
Wow, that's another reason why you will probably wont carry
it around in your pocket any times soon. But it's
an important actually point to make, is that people will
build these systems and go to the larger scales. They
can and spend a lot of money to try to
do the first demonstrations, but we'll have to shrink them
and make the more cost effective all the components that
go in.
Speaker 1 (30:18):
Eventually, it's like we did for any algorithm.
Speaker 3 (30:21):
Yeah, exactly, and that part will happen. It just requires
you to start building these larger systems and for the
companies that are making the individual components for them to
have larger volumes so they can.
Speaker 2 (30:30):
Drive on costs.
Speaker 3 (30:31):
But where it's particularly challenging right now is actually in
the control electronics. Like the costs about maybe ten thousand
dollars a little more than ten.
Speaker 2 (30:39):
Thousand dollars just for the control used for every single fewbit.
Speaker 3 (30:43):
Wow, and we need to go to maybe a million
few bits or something. So that's like ten billion dollars
just in the control hardware right if we were.
Speaker 2 (30:50):
To scale out what we have today.
Speaker 3 (30:52):
So it's very costly to imagine doing that, so right now, yeah,
but then we'll get better. We'll do custom silicon chips,
where the costs are in the scale of the electronics
is much more efficient, So we'll do what are called
ASEX or custom circuits that'll drive down costs tremendously, but yeah,
that that has to happen, but it just you know,
it's not We're not quite there yet.
Speaker 1 (31:11):
So there you have it. You can build a quantum
computer in your garage right now for about a million dollars,
although for that money right now, you could only put
about twenty cubits on it, which is about as sophisticated
as an abocus, although this case would be a quantum ebicus. Right.
The last thing we'll talk about is why quantum computers
(31:31):
are so hard to make. If they can break any
encryption on the planet, or potentially let us simulate new
chemicals and materials, why haven't we done it? What is
so hard about making a quantum computer? Here's Oscar explaining it.
Speaker 3 (31:45):
Probably the thing that makes it most difficult, and maybe
it's the most relevant to talk about, is that let's
say you want to do a computation with a quantum computer,
and you want to describe it by a certain number
of particles, and you want to use those particles to
do your quantum simulation. Then you need to be able
to control those particles right, to manipulate them to do
the computation you want. But if those particles interact with
(32:07):
the environment, then part of the information that you wanted
to control or manipulate will actually evolve and become connected to.
Speaker 2 (32:15):
These other particles.
Speaker 3 (32:16):
And that's the really tricky problem is how do I
control tiny little quantum particles with my grubby little hands,
so to speak. So I have to be able to
send in these control signals to and manipulate these quantum particles,
but I can't let in any other parts of the
environment in the same time, and so it becomes a
really hard problem to sort of shield the system you're
(32:39):
trying to use to do this computation, but then also
allow yourself these control knobs.
Speaker 1 (32:44):
Is it like a question of purity to.
Speaker 3 (32:46):
Some degree, yes, Like the properties electron have to be
just that electron, and they interact with other things that
you're not able to control, you lose the information.
Speaker 2 (32:56):
All right.
Speaker 1 (32:57):
So the reason that quantum computers are so hard to
make and run basically goes back to Schrodinger's cat. Might
have heard of this analogy when people are talking about
quantum things, And the idea is that if I take
a cat and I put it inside a box, and
I also put in the box a quantum particle that
might kill the cat. Then when I close the box,
(33:19):
eventually the cat becomes both alive and dead at the
same time. And that's because when I close the box,
the quantumness of that killer particle basically extends to the
cat itself. Now, a quantum computer is basically like taking
a whole bunch of those boxes with cats that are
alive and dead at the same time, and it tries
(33:41):
to do math with them. And because all those cats
are in that magical quantum state of being two different
things at the same time, alive and dead, then you
can do some really powerful computations with them, like multiply
a whole bunch of numbers all at the same time.
But as soon as anyone takes a peek inside one
of those boxes and the whole thing collapses. As soon
(34:02):
as you open one box and you see whether the
cat is alive or dead, then that box loses its
quantum magic, and all the other boxes that are talking
to it will also lose their quantum magic. So the
reason you need to build giant refrigerators and keep these
computers in an almost perfect vacuum with perfect coldness is
to protect them from any random bit of motion or
(34:24):
energy from essentially peeking inside your quantum boxes, because if
that happens, the whole thing collapses and stops working. And
this problem only gets worse as you make the computers
bigger and more complicated. But people like Oscar are getting
better and better at it. Well, that was great, that
was awesome. I guess just the last question, what is
(34:45):
the current state of the art in quantum computers?
Speaker 3 (34:48):
Yeah, so I think that if you can look at
this on I would say three axis, so you can
ask how many physical cubits can I make in.
Speaker 1 (34:55):
Control right now?
Speaker 2 (34:56):
Right?
Speaker 1 (34:56):
What's the highest number of somebody that has been So.
Speaker 3 (34:58):
If you just said I just want to be to
control this many cubits, it's a few hundred. And people
have made systems of more than a few thousand, but
maybe not controlled all of them simultaneously. But people have
definitely made a few hundred and controlled them. So we're
getting to that level. And you might say, well, okay,
put that in context, and if we could control them
(35:19):
with high enough fidelity and not make errors, we would
be at the point where we could actually start to
access and solve problems of practical utility better than we
think other computers can, like we could answer some of
these questions about how electrons interacted materials, like small toy problems,
but still useful.
Speaker 1 (35:35):
So like, if I have a thousand cubits working, yeah,
what kinds of passwords can I break? Right now?
Speaker 2 (35:40):
Yeah?
Speaker 3 (35:41):
So, like the number of bits and an RSA key
is like a few thousand, So if I had a
few thousand cubits, I could crack RSA a.
Speaker 1 (35:49):
Few thousand, and we're at one thousand now. Yeah, so
right now we can maybe crack simple passwords.
Speaker 3 (35:55):
Like yeah, surely that's right, shorter short of ones that
we can already do classically, So probably not useful, but
we're within striking. But the bigger problem is that we
can't do those calculations because our calculations are too air prone.
Speaker 2 (36:06):
Then we need to add the air correction.
Speaker 1 (36:08):
Okay, that's the other that's the root axs.
Speaker 3 (36:10):
And that's adding redundancy, and so really think about it this.
I need to not have just a few thousand physical cubits,
but I may need a few million because the redundancy
factor is pretty large right now, Like if my hardware
had no errors, I wouldn't need to do any air
correction and the redundancy factors one. But I do have errors,
and the errors we have right now require about another
(36:30):
factor of one thousand overhead a thousand cubits multiple thousands
of times, so it'd be a thousand times of thousand,
which is a million. If I need a thousand cubits
to do computations with, I have to multiply that by
one thousand, and that gives me how many physical cubits
I need to represent?
Speaker 2 (36:46):
Oh wow, So.
Speaker 3 (36:47):
That's why I'm saying we probably needed like a million
physical cubits. So that's what people are doing right now.
The fact is that we can actually build and control
on order a few hundred one thousand cubits is amazing, right,
that's huge progress.
Speaker 1 (36:58):
Like ten years ago it was z there are cubits.
Speaker 3 (37:00):
I would say we became masters of the individual cubit
so to speak. Maybe even in two thousand we're really
really good at that. It was very hard to first
even figure out, like to control a single cubit. But
since then we've been already growing small cubit systems and
improving how the interacting in the gates that we can implement.
There was a recent result where scientists at Google showed
(37:21):
that their processor would require ten twenty years for a
classic computer to simulate what they've done the processor. You know,
our own team hit Amazon. We focused on a slightly
different hardware implementation that potentially has an ability to reduce
the hardware overhead by factors on the order five to ten,
which could be very important. So, even though it doesn't
(37:43):
have a practical application yet, it's clear like there's a
big difference in the power of what these things can do.
There are a set of problems that the class computers
are just not going to be good at, and there's
going to be a set of things that quantic computers
can do that classical ones cannot mimic. And if you're
watching this as a sort of an interested techy observer
and look looking for a turning point or a tipping point,
I'd be watching for how these air rates go down,
(38:04):
how efficient air correction is in these sort of one
hundred two thousand cubit systems over the next few years.
Speaker 1 (38:10):
Very cool, Well, thank you so much, Oscar. That was fantastic.
Speaker 3 (38:14):
Yeah, I hope we got into enough of the detail
where it's understandable enough. It is definitely a difficult subject
and there's a lot of hype around it. Even for me,
it's very hard to read the news and to decipher
what is really an advance of what isn't. And I'm
deep in the field, so I can only imagine for
others that read about it.
Speaker 2 (38:31):
Very cool, right, all right?
Speaker 1 (38:33):
Thanks a lot, yep, and that is how a quantum
computer works. Thanks for going on this field trip with me.
I hope you enjoyed that. See you next time. You've
been listening to Science Stuff. Production of iHeartRadio written and
produced by me or Hitchm executive producer Jerry Rowland, an
audio engineer and mixer Casey peckrom and you can follow
(38:55):
me on social media. Just search for PhD comics and
the name of your favorite Be sure to subscribe to
Sign Stuff on the iHeartRadio app, Apple Podcasts, or wherever
you get your podcasts, and please tell your friends We'll
be back next Wednesday with another episode.
Hey, welcome to Sign Stuff, a production of iHeartRadio. My
name is Jorge cham and to the end of the program,
we are talking about a technology that may potentially impact
the life of every single human on Earth. It might
change how we protect data and come up with passwords,
it might help us make new and exciting materials, and
it might render cryptocurrencies like bitcoin and dotgecoin totally useless.
(00:26):
I'm talking about quantum computers. What are they, how do
they work? And most exciting is that we're going to
get to visit one of them and actually hear it
in action. So power up your curiosity, log in, and
let's answer the question how do quantum computers work? Hey? Everyone? Okay,
(00:48):
so when I started this episode, I was both terrified
and excited. Terrified because explaining anything with the word quantum
is really hard, but excited because I had heard that
a friend of mine was making quantum computers just ten
minutes from my house, and this was a great excuse
for me to go take a look at them. So
we're going to go see these quantum computers in person
(01:10):
at the end of the episode, but before that, I
wanted to make sure that I understood what they were
how they work, and also what they're potentially going to
be used for. So this episode is split into three parts.
What is a quantum computer and how does it work?
What are quantum computers for? And then we're going to
go see the quantum computers and we're going to talk
(01:30):
about how they're made and why they're so hard to
get them to work. Our guide through all of this
is going to be my friend who's making the quantum computers,
Professor Oscar Pater. He's a professor of physics and applied
physics at Caltech and he's the head of quantum hardware
for Amazon. He does research on nanophotonics, quantum optics, and
of course quantum computers. Here's my visit to Oscar Painter's lab.
Speaker 2 (02:00):
Ah, hey, Oscar, how are you good to see you
after so many years.
Speaker 1 (02:04):
Yeah, it's been a while. Huh yeah, well thanks so
much for talking with me.
Speaker 3 (02:07):
Yeah, it's been a while. Happy to try to fill
you in on some of the things we've been doing
in the areas of quantic computing.
Speaker 1 (02:13):
Okay, so the first thing I wanted to talk to
him about was just what does the word quantum mean?
Because I feel like we're going to need that to
understand what a quantum computer is. Now, the word quantum
is the word we used to describe how things behave
at the level of atoms and the tiny little particles
that make up the atoms. So in our everyday lives,
(02:35):
we're used to things being solid and us being able
to hold them, like, for example, if you take a
piece of wood or a ball. But if you take
that piece of wood or ball and you chop it up,
and you keep chopping it up, you get down to atoms,
and then you'll notice that those atoms don't behave in
the same way that a piece of wood or a
ball do. Here's how Oscar explains it.
Speaker 3 (02:55):
It turns out that down to the microscopic scale, so
not our everyday scale of things, the laws of physics
that dominate in that regime is quantum mechanics, and quantum
mechanics is a theory that has some strange attributes that
we don't experience every day. For example, it postulates that
things can be in superposition, so you can have objects
being in sort of what we think of as two
(03:17):
distinct realities at the same time. Imagine having a particle
in one position and another position simultaneously. That seems very
odd to us, but in quantum mechanics it's very natural.
Speaker 1 (03:28):
Like, for example, I grabbed this piece of wood in
front of me, and it's a piece of wood. It's
not two things at the same time. Right, It's in
one location.
Speaker 3 (03:35):
Right, it's sitting there. It's firmly right in front of you.
Speaker 1 (03:37):
Right. If I had an atom in front of me
or an electron, it wouldn't exactly.
Speaker 3 (03:42):
You would find that if you repeated the measurement or
finding its position multiple times, you might find that, Oh,
I get this weird outcome that sometimes I measure it here,
sometimes I measure it there. And that's because it's actually
in many places at once, all right, And that's fundamental
to the description of quantum mechanics. The way I like
to think about quantum mechanics is really as waves and amplitudes.
(04:03):
So think about you're at a pond and you throw
a rock in a pond, and you see this ripple
of the rock. Right, That's how I think about, Like
the rocks are sort of the particles, and these wave
phenomena are sort of the actual physical quantum mechanical description
of that particle.
Speaker 1 (04:18):
Like the particle the thing, the atom or the electron.
It's not the rock you throw into the pond, no,
but it's actually the ripple of the ripple.
Speaker 3 (04:25):
Yeah, that's right, it's this wave. So I may have
started with something that was very local, like that rock,
but then it becomes very quickly it sort of propagates
out and is actually better described as this wave on
the pond.
Speaker 1 (04:36):
Because like a ripple and a wave in a pond
like that, it's kind of in a lot of places
at the same.
Speaker 3 (04:40):
Exactly, that's right. And then the interference is important to understand.
If I throw two rocks in the pond, then I
see the sort of interference of the ripple patterns coming
from each rock that blashed in the pond.
Speaker 1 (04:51):
Right, Like each ripple starts at simple, but then they
start to mix together and form this complex pattern on
the surface of the pod.
Speaker 3 (05:00):
Exactly, like how do they evolve in time?
Speaker 1 (05:03):
Okay, so when you get down to the level of atoms,
things behave really strangely. Scientists think of things at that
level not as little tiny balls, but as waves or
ripples of energy, like the ripples in a pond. Now
you may think, wait a minute, if things are kind
of wavy and strange at the level of atoms. Why
isn't it that way when you get to big stuff
(05:25):
like a piece of wood or a ball, And the
answer is that they are that way. There's just a
lot of atoms in a piece of wood, and from
a distance, it gives you the impression that it's solid.
It's sort of like how some clouds from afar they
might look solid once you get up close to them,
they're actually kind of fuzzy and wispy, and all the
(05:46):
water droplets are moving around. So that's quantum. Now. A
quantum computer is what happens when you make a regular computer,
but you make the circuits out of individual atoms or
particles like electrons.
Speaker 3 (06:00):
Classical computers are formed from things that are very very
classical in nature.
Speaker 1 (06:04):
And they uperate kind of on hard switches.
Speaker 3 (06:07):
Yeah, like, yeah, that's right, the transistors on your phone,
And that's what we call these types of elements. The
transistors are used to store information or perform calculations, and
the transistors are really set by a bunch of electrons
in part of the circuit. And usually you're talking about
quite a few electrons.
Speaker 1 (06:21):
Because regular transistors are huge. They're bigger than an atom.
Speaker 3 (06:25):
Yes, exactly, that's physically what's going on in your phone.
And what I'm telling you is that the way to
think about it is in the quantum case, I just
have one electron.
Speaker 1 (06:34):
Like the circuits are made out of individual electrons.
Speaker 3 (06:37):
Yeah, atoms is exactly what you're doing. Or a quantum
particle doesn't have to be electrons, can be other particles.
That was the sort of very early idea from people
like FIM and others back in the nineteen eighties is
if you're going to do this, and you better make
them out of quantum mechanical objects to begin with.
Speaker 1 (06:53):
Okay, So if you make a computer where the circuits
are made of individual quantum objects like atoms or electrons,
then you get a quantum computer. And what that does
is that it makes their calculations also quantum mechanical. And
this is where the concept of a cubit comes in.
It's like a regular bit in your computer, and a
(07:13):
bit is like a one or zero, but a cubit
is a quantum mechanical one or zero.
Speaker 3 (07:20):
Classical computers are formed from digital bits and they go
between one and zero. A quantum computer doesn't have these
hard zero one states. It has every possibility in between.
So imagine if we have these two states zero in one.
I told you that a quantum system can be in
two different states at once, right, So it can be
in zero and one at the same time, and I
(07:42):
can have a different weight of zero or one at
the same time. It could be ten percent zero, ninety
percent one.
Speaker 1 (07:48):
It's like a shade of gray.
Speaker 3 (07:49):
Yeah, And so you have all those possibilities in between.
It can be zero or one or anything in between.
Speaker 1 (07:55):
It can be black, white, dark, gray, light.
Speaker 3 (07:58):
Gray, exactly, So it has all those shape in between.
You can take zero with some fraction and add it
to one with any other fraction. You can have any
combination of that.
Speaker 1 (08:07):
So on a regular computer, if you multiply two bits together,
it's like you're multiplying two fixed numbers together, like three
times four. But in a quantum computer, when you multiply
two cubits together, it's like you're multiplying two things that
can be lots of numbers at the same time. So,
for example, it's like you're multiplying every number from zero
(08:28):
to one hundred times every number from zero to one thousand,
all at the same time in one operation. That's what
makes quantum computers unique. They take this weirdness of the
quantum world and then let's you do math with it. Now, Actually,
it's not doing all of those multiplications or calculations at
the same time. It's more like how Oscar described it earlier.
(08:49):
If you drop two rocks in a pond, you see
the two ripples spread out and mix together to form
a complex ripple pattern. That's more of the picture of
what a quantum comp does. It doesn't do calculations with
hard numbers. It does calculations with the ripples and patterns
of quantum numbers. Of course, my next question for Oscar
(09:10):
was what is that good for? Why would you want
to do math this way? When we come back, I'm
going to ask Oscar what quantum computers are for, and
then at the end we're going to go check out
the ones he's built. You're listening to sign stuff. Welcome back. Okay,
(09:35):
to recap, we learned that a quantum computer is a
regular computer whose circuits are made with individual atoms or
small particles like electrons, and by doing that you can
do quantum calculations. That is, you can do math, but
with numbers that are actually lots of different numbers at
the same time. So now the question is, why would
you want to do that? What are quantum computers? Four?
(09:58):
Here's more of my conversation, but quantum physicist Oscar Painter.
Let's say it's a few years into the future and
we have quantum computers, yes, in our phones, like I
have one in my podget Okay, what can I do
with it? And how is my life different?
Speaker 3 (10:13):
I think that's a very unlikely scenario.
Speaker 1 (10:16):
Okay.
Speaker 2 (10:17):
I think that's the wrong way.
Speaker 3 (10:19):
To think about how quantic computers might change our lives,
at least as far as I can project into the future. Okay,
I think the best way to think about a quantic
computer as we envision it right now is that it
will be more.
Speaker 2 (10:33):
Like a supercomputer.
Speaker 3 (10:34):
So a supercomputer is just a very large computer that
can perform calculations beyond what our desktop, our personal computers
can do. And these are usually very large, almost building
scale computers and computer clusters that have many, many different
processing units that are all integrated together, and through that
scale you can perform a huge number of computations per
(10:55):
second and therefore compute some of the hardest problems.
Speaker 2 (10:58):
That are out there.
Speaker 3 (10:58):
A lot of them are used for chemistry problems. They're
used to study particle physics, so fundamental physics, trying to
understand models of quantum particles that are beyond the current
standard model. They're used to compute the properties of materials,
climate modeling, and things like that.
Speaker 1 (11:14):
So usually science and tech, yeahs, And.
Speaker 3 (11:17):
There's always this competition between different nations who has the
fastest or the biggest supercomputer.
Speaker 1 (11:22):
I see, So you envision quantum computers will be sort
of like a specialized version of computer.
Speaker 3 (11:28):
It's going to be some very special type of supercomputer
that can solve specific problems that quantum computers will be
very effective at that we can't do today on classic computers,
no matter how much we scale them up. And the
key is it's not just a faster supercomputer. It performs
calculations in a fundamentally different way, and therefore it can
tackle problems that are possibly outside of the reach of
(11:49):
these conventional classical supercomputers.
Speaker 1 (11:52):
What do you mean? Out of the reach meaning that.
Speaker 3 (11:54):
No matter how fast they get or how big they get,
they'll never be able to compute some of these problems,
never or take an infinite exactly, it's just the scaling
is so bad for these problems, you would take way
too long and require way too large on machine. So,
no matter how hard we work on our current computing technology,
it has limits and it's known and you can prove
(12:16):
it for certain problems, and quantic computers when they looked
at theoretically these same problems, they realize that the same
restrictions or limitations for quantic computers are not there. There's
examples where we believe and strongly believe that certain mathematical
problems that are important are really really hard to perform
(12:38):
and can't be solved using classical means, no matter how
much we improve the technology.
Speaker 1 (12:42):
No matter if I have a building full of supercomputers,
yeah exactly, you'll never be able.
Speaker 3 (12:46):
To just fill the world with them. You still won't
be able to do it. Yet a quantic computer can
solve it pretty efficiently.
Speaker 1 (12:53):
Well. Step me through some of these problems.
Speaker 3 (12:55):
Like so the example that everyone points to, and it
is pretty amazing that people found this, But there's this
mathematical problem. It just happens to be very applicable to
our safety or security of our data. So it turns
out that most of the security of all of the
data that you hold, all the data that banks or
various institutions around the world want to be safe and protected,
(13:18):
they typically encrypt it. And those encryption techniques that have
been used were what are called RSA encryption, where you
want to take a large number and understand what its
prime factors are.
Speaker 1 (13:29):
Okay, so the first big thing that quantum computers can
be useful, the one that got people really excited about
them in the nineties, is in breaking password encryption. So
whenever you enter your password on a website or when
you download your bank statement, that information is encrypted or
scrambled so that if anyone happens to catch that information,
(13:51):
they can't tell what it says. And the whole scheme
is based on the idea that if I gave you
a really large number, it's really hard to find what
its prime factors are. Here's how Oscar explains it, but
just to give you a quick heads up, a prime
number is a number that can't be divided except by
itself or by one. So, for example, thirteen is a
(14:14):
prime number because you can't fight thirteen by anything except
thirteen and one, And the same goes for seventeen nineteen
twenty three and so on. Anyways, here's Oscar explaining it.
Speaker 3 (14:27):
So I give you a number and I say, tell
me what the prime factors are, and you have to
break it down to its prime factors. So you know,
a simple one is, you know, like two, it's just
one times two, one and two. Those are the two
prime factors, right. But it gets harder as these numbers
get bigger.
Speaker 1 (14:41):
If I tell you one millions be round there and
forty three.
Speaker 3 (14:44):
Yeah, seventeen, very hard to actually answer what those what
the prime factors are. But if I give you the
prime factors, you can multiply them together and very quickly
get the answer to what that larger number is.
Speaker 2 (14:56):
Right.
Speaker 3 (14:57):
And so if you know the prime factors, I can
give you what they multiply to.
Speaker 2 (15:00):
But if you give me.
Speaker 3 (15:01):
The number that they multiply to without then I have
a very hard time finding out what the prime factors are.
Speaker 1 (15:06):
Because you'd have to get kind of have to guess.
Speaker 3 (15:09):
Well, you know, there's mathematical techniques to try to find these,
but they're very inefficient.
Speaker 2 (15:14):
And so it turns.
Speaker 3 (15:15):
Out that most of the security of the way we
encrypt information is based upon that asymmetry. And how hard
the problem is.
Speaker 1 (15:23):
So, now, let's say somebody has a quantum computer.
Speaker 3 (15:25):
Right, then they can find those prime factors and they
can now decrypt all that information.
Speaker 1 (15:32):
They can just grab it from the air, yeah, and
be like, oh, I know.
Speaker 3 (15:35):
And yeah, I can find the prime factors and then
I can use that to decrypt the information.
Speaker 1 (15:42):
That would be easy for a quantum computer, and you
just press a button and will tell you, oh, this
is an oscar or his secret decoder.
Speaker 3 (15:48):
Yeah, exactly, So that would you know. That obviously concerned
a lot of people when that algorithm was developed.
Speaker 1 (15:58):
Okay, this gets a little bit heavy into encryption and
quantum algorithms, but the main point is that most of
the security of our passwords and our sensitive information, and
also the encryption of things like bitcoin and all those cryptocurrencies,
they all depend on this one math problem which is
really hard for regular computers even supercomputers to solve. And
(16:20):
that is a problem of finding the two prime numbers
that multiply to get a really large number. But then
in nineteen ninety five, a computer scientist named Peter Shore
publish the paper titled Polynomial time Algorithms for prime factorization
of discrete logarithms. On a quantum computer, which essentially showed
that if you have a quantum computer, you can solve
(16:40):
this problem in a short amount of time. And this
is probably the main reason that people have been rushing
to make quantum computers since then, because imagine if everyone
in the world, people, companies, countries are all protecting their
secrets using the same trick, but you had a special
quantum computer that could break that trick, you could rule
the world. Now, the details of how Peter Shore's algorithm
(17:03):
works are a little complicated to explain here, but the
essence of it is that you're using the ripples on
a pawn nature of quantum numbers on a quantum computer
to basically try out every possible combination for how to
break your secret encryption, and you use some clever math
tricks so that these ripples combine and mix together until
(17:23):
the right answer pops out. So that is the main
reason that people are excited about quantum computers. But there
are other reasons and other possible applications, So here's Oscar
telling me about them.
Speaker 3 (17:37):
Another example is maybe more natural to think about, and
this is where quantum computers were first proposed. It to
be interesting or useful, and that is the simulation of
nature itself. Nature as we know it is not classical.
If you peel the layers of the onion enough and
you get down to the core, right to the atomic scale,
it turns out that the laws of physics that dominates
(17:59):
quantum mechanics, okay, like the actual mathematics of that, when
you describe it, when you have many particles, it quickly
becomes something that you can't simulate with a classical computer.
So all those interference of all the particles and keeping
track of all of that. A classical computer, if you
try to simulate that, you quickly run out of steam
and it becomes an exponentially hard problem. And so you know,
(18:21):
a classical computer is just ill suited.
Speaker 2 (18:23):
To doing that.
Speaker 3 (18:24):
But a quantum computer that's made out of the same
those sort of particles that can do with that interference naturally,
you know, has a natural advantage in terms of using
it to simulate the natural world at its quantum mechanical core.
Speaker 1 (18:35):
Why would I want to do that?
Speaker 3 (18:36):
Yeah, So that's the questions like, okay, so that's great,
but why would I want to do that other than
maybe I want to understand physics better? Well, this idea
that I want to understand how material behaves is a
very good example. If I'm building an electrical circuit, or
I'm building a new battery, or I'm building a different
energy process inside of a material or energy storage device.
A lot of times that depends on what the electrons
(18:57):
are doing. If I want to understand or something unique
when I describe them quantum mechanically, maybe there's special properties
I'm just totally blind to. So if I wanted to
make a better superconnecting material, something that can carry electricity
with no resistance, right, maybe we can have magnetically livitated trains.
Maybe you can have you know, really efficient electrical circuits
(19:18):
that don't dissipate any energy.
Speaker 2 (19:19):
All of these things.
Speaker 3 (19:20):
Then I would have to use a quantum computer to
model that behavior.
Speaker 1 (19:23):
And you said there's some maybe potential applications in chemistry
and biology.
Speaker 3 (19:27):
Yeah, you know, if I think about what is going
on when I have a chemical reaction, usually it comes
down to the electrons, and I need to understand what
they're doing in order to understand, you know, whether this
chemical reaction is going to be efficient or not, or
if I want to describe it with chemical accuracy, so
I can use it to, you know, do some sort
of industrial chemical process. The biological application. It's like, if
(19:48):
I want to know how molecules are biologically relevant molecules
lined together, then potentially I need to know more information
about the electronic behavior in these molecules. If I wanted
to do that without having approximation or much higher accuracy
than a quantum computer would be potentially more capable.
Speaker 1 (20:04):
There I we might be able to predict better how
a vaccine will work, or whether a certain chemical introduce
in your body will.
Speaker 3 (20:11):
Right now, we don't have that sort of level of specificity.
I mean, we'd love too. People are proposing techniques, but
that's the right idea, by the devil's in the details.
And you know, you have people saying, well, look, you know,
I think even today there's I won't call them skeptics,
but there's a lot of people that are saying, well,
I can keep improving my classical algorithms, and whether you
can really gain advantage from the quantum simulations is a
(20:34):
it's a practical question, and maybe we don't have as
clear an example or as clear a win when it
comes to how quantum computers will will do better, or
be more efficient, or be able to do the calculations
fast or even do them ones that the classical computers
can't do. But I think there's definitely something there. It's
just that we still have to work on a quantum algorithms.
It's not as clear cut, I would say.
Speaker 1 (20:55):
So those are the two main applications or uses for
planted computers. One is in breaking encryption using a special
algorithm called phase estimation that only works in a quantum computer,
and the other is to simulate nature, because nature is,
after all quantum at its core, and so scientists think
that quantum computers will let us better simulate how atoms
(21:18):
and electrons interact so that we can design better materials,
better semiconductors, and maybe better medicines. Now, I said so far,
because this is all still very new, and there might
be other classes of problems like the encryption problem where
quantum computers are just fundamentally and exponentially better at solving,
(21:39):
but nobody knows for sure. Of course, it's all hinges
on whether or not we can actually make quantum computers
at the level that they would actually be useful and
most important, reliable. So now we're going to go actually
see these quantum computers that Oscar is building, and he's
going to tell us why they're hard to make and
why they're so prone to making errors. But first, let's
(22:00):
take a quick break. You're listening to science stuff and
we're back. Well I heard you have a quantum computer
in your basement.
Speaker 3 (22:16):
Well not in my basement, but in my my laboratory. Yeah, here,
can we go see it?
Speaker 2 (22:21):
We can?
Speaker 1 (22:22):
Okay, yeah, let's get see it.
Speaker 2 (22:23):
Okay, you want to do that?
Speaker 1 (22:24):
Okay, so where are we going?
Speaker 2 (22:28):
Just the next door.
Speaker 3 (22:29):
We don't actually even have to go down into.
Speaker 2 (22:31):
The basement, into the basement, no.
Speaker 1 (22:34):
Basement sound and more.
Speaker 2 (22:36):
Yeah, i'd scientists exactly.
Speaker 3 (22:37):
So let's all these labs have different variants of quantic
computers that we're testing. Multiple quantum computers here, yeah, yeah,
not just one. So there's small scale quantum computers, but
the largest ones are you know, ones at at Amazon
or Google or IBM or you know some of the
(22:58):
other startup companies. These get to be maybe a factor
of ten times larger than the ones I'll show you. Okay, okay,
so this gives you an idea. All of these control electronics,
right is to use to control about twenty of these
quantum bits.
Speaker 1 (23:12):
There's twenty quantum meaning twenty particle. A machine made up
of twenty quantum particles.
Speaker 3 (23:18):
Corract right, which we are manipulating as quantum bits, and
that circuit lives down inside of this special refrigerator.
Speaker 1 (23:26):
Okay, So if you've ever seen, or if you google
a picture of a quantum computer, most likely what you
see is something that looks like an upside down metal
wedding cake with circular tears or platforms that get smaller
and smaller as they hang down from the ceiling. That
is basically a super intense refrigerator. The whole purpose of
(23:49):
it is to get the tip of that upside down
cake really really really cold.
Speaker 3 (23:56):
And this refrigerator is under vacuum, under high vacuum. It's
a temperature which is about ten million degrees above absolute zero.
Speaker 2 (24:03):
Ten degrees.
Speaker 3 (24:04):
So to give you an idea, So if I go
to the deepest part of space, it's a few degrees calvin,
a few degrees above that food and zero, the coldest
darkest parts of outer space or that universe. Yeah, but
this thing's about thirty times colder than that.
Speaker 1 (24:18):
Even WHOA So would you say that some of the
cold this places in the whole universe.
Speaker 3 (24:25):
I mean no, I mean you can get there's people
that do this for a living that make really cold things.
Speaker 2 (24:29):
But this is among the very very coldest things. Okay, yeah,
but this is extremely cold.
Speaker 1 (24:34):
What does it need to be cold?
Speaker 3 (24:36):
Because even the lights, even if we turned all the
lights off, even just the fact that the room's hot, it's.
Speaker 2 (24:42):
Room temperature, but it radiates.
Speaker 3 (24:44):
Radiation, and that radiation would completely destroy the information in
the corner bit.
Speaker 2 (24:49):
I see. We have to get it really dark.
Speaker 3 (24:51):
We have to make sure that there's not any of
this thermal energy that's making it into the circuit, otherwise
it'll destroy the manipulation of those quantum parties. And so
it has to be as isolated as we can from
the environment. We would ideally seal it off from everything,
so it would be like zero temperature and there would
be nothing coming in other than what we want to
send to it to control it.
Speaker 2 (25:10):
And then you can see there's all of these cables,
uh huh. Each of these feeds.
Speaker 3 (25:14):
Into a microwave cable that could use to control individual
quantum bits or quantum particles on the circuit.
Speaker 1 (25:22):
So what I'm looking at is a room full of
electronics and cables, and in the center is a massive
structure with two suspended eye beams, and hanging from those
beams is the upside down wedding cake I mentioned before,
which in this case is sealed inside a really thick
metal cylinder, and inside that cylinder at the very tip
(25:45):
of the wedding cake cool to almost the coldest anything
can be in the whole universe. Is a little chip?
Good a quantum computer?
Speaker 2 (25:54):
Well?
Speaker 1 (25:55):
What's in there? So describe me what's inside the core
of it? Is it like a little chip? Yeah?
Speaker 2 (25:59):
Like love.
Speaker 3 (26:00):
It's what's called a superconnecting quantum circuit. So it uses
little metal traces on a silicon wafer that we pattern
on the surface, and when you get them cold enough,
they become super connecting, which means they can carry electrical currents.
Speaker 2 (26:12):
Without any energy dissipation.
Speaker 3 (26:14):
Okay, And it turns out that you can form these
sort of quantum particles like these atoms, where the current
is circulating in a clockwise way inside of a little
tiny ring, or it's circulating counterclockwise, and the clockwise could
be zero, when the counterclockwise could be one, and you
can get in any superposition of these two circulation patterns,
and I can use then I can manipulate what the
(26:35):
superposition is, and I can have interact with other circulating currents.
Speaker 2 (26:40):
To the things in our circuit.
Speaker 3 (26:43):
There are a few hundred microns in size, so they
might be a few times the human hair diameter, so
they're pretty big relative to conventional transistors. It's made out
of many atoms, but it behaves like a single atom.
Speaker 2 (26:55):
Okay, yeah, the way to think about it.
Speaker 1 (26:57):
So there's like a little array of these things, a.
Speaker 3 (26:59):
Little array of these things on the surface of a microchip,
and then each of them we can control the current flow.
So what are called single cubit gates. We bring them
together and then let them interact them bring them apart.
So I need to be able to manipulate the single particle,
put it in any sort of superposition I want.
Speaker 2 (27:13):
And then you have to read out the state of
these cubits too.
Speaker 3 (27:15):
You have to know after I do my computation, are
you in state zero or state one? All right, I
have to ask that question for all my cubits, and
that will give me the answer.
Speaker 1 (27:23):
I see what is that hearing?
Speaker 3 (27:25):
So this is called the pulse tube cooler sownders sounds
like if you were ever a kid growing up in
the eighties and you watch Battlestar Galactica or the Cylons
and Battlestar Galactica, they do they walk, and they would
have this flashing light and they'd have this sort of
sound coming from them.
Speaker 2 (27:39):
This is a similar sort of sound.
Speaker 3 (27:40):
This is a pulse tube cooler and it's shooting a
slug of helium gas onto a cold plate and then
in doing so, when it expands, it can cause cooling.
It's analogous to what you do with the regular refrigerator.
That's the first stage of cooling, though that only gets
you down to maybe a tenth of the temperature of
the room. And then if I want to go even
cooler down and by another factor of ten or one hundred,
(28:01):
then you have to use a recirculating gas.
Speaker 2 (28:03):
In this case, it's a dilution fridge that takes mixtures
of isotopes.
Speaker 3 (28:07):
Of helium helium three and helium four, and when they mix,
there's an entropy of reaction and that's what gets you
down to this lowest temperatures I mentioned.
Speaker 1 (28:14):
So it's several stages. Something like take a fridge put
it inside of another fridge.
Speaker 3 (28:19):
So there's actually like sort of three or four stages
of if you're inside of a fridge and you have
instead of the fridge, the one fridge is too hot
for the other fridge, so we have to isolate them,
and then we have to do that for every successive stage.
Speaker 1 (28:32):
It's like, if I take my freezer and I put
it inside of like a restaurant freezer, just be colder.
Speaker 2 (28:37):
Yeah, okay, exactly, I keep doing that. I add, you know, another.
Speaker 1 (28:39):
Way, the fridge inside of my fridge have a restaurant freezer.
Speaker 3 (28:42):
And I keep you know, each of them has the
ability to get colder and colder. Yeah, So you have
to do it in stages. Otherwise, if you try to
do a direct shot, it's too much of a thermal
load on the system.
Speaker 1 (28:50):
I see. So that's a quantum computer in action. Most
of what you see when you look at a picture
of a quantum computer, it's all the machinery needed to
keep the actual circuit in a near perfect vacuum and
as cold as possible, and all of that is to
completely isolate the quantum computer from the outside world. We'll
(29:11):
get to why you need to do that with a
quantum computer. But first I was curious how much a
quantum computer like this costs. Here's what oscars it. Well,
this is definitely much bigger than my phone.
Speaker 2 (29:23):
Yes, exactly.
Speaker 3 (29:24):
That's why I was saying, you're probably not going to
carry one of these things around.
Speaker 1 (29:27):
How much is this something like this if I wanted
to build one in my garage?
Speaker 3 (29:31):
Okay, Well, you know there's always a big difference between
science money and money that you know, when you're talking
about conservative products that have large volumes. I remember the
first time we purchased a big piece of equipment from
my lab when I was the first a faculty member.
Speaker 2 (29:43):
It was about the same.
Speaker 3 (29:45):
It was about smaller than this thing, so smaller than
a few cubic feet, but it was more expensive than
my house when I bought it.
Speaker 2 (29:52):
So there's a big difference. Cot So just keep that
in mind.
Speaker 3 (29:55):
But one of these systems today, because it's very specialized,
probably costs about a.
Speaker 2 (29:59):
Million dollars set up.
Speaker 3 (30:00):
Wow, that's another reason why you will probably wont carry
it around in your pocket any times soon. But it's
an important actually point to make, is that people will
build these systems and go to the larger scales. They
can and spend a lot of money to try to
do the first demonstrations, but we'll have to shrink them
and make the more cost effective all the components that
go in.
Speaker 1 (30:18):
Eventually, it's like we did for any algorithm.
Speaker 3 (30:21):
Yeah, exactly, and that part will happen. It just requires
you to start building these larger systems and for the
companies that are making the individual components for them to
have larger volumes so they can.
Speaker 2 (30:30):
Drive on costs.
Speaker 3 (30:31):
But where it's particularly challenging right now is actually in
the control electronics. Like the costs about maybe ten thousand
dollars a little more than ten.
Speaker 2 (30:39):
Thousand dollars just for the control used for every single fewbit.
Speaker 3 (30:43):
Wow, and we need to go to maybe a million
few bits or something. So that's like ten billion dollars
just in the control hardware right if we were.
Speaker 2 (30:50):
To scale out what we have today.
Speaker 3 (30:52):
So it's very costly to imagine doing that, so right now, yeah,
but then we'll get better. We'll do custom silicon chips,
where the costs are in the scale of the electronics
is much more efficient, So we'll do what are called
ASEX or custom circuits that'll drive down costs tremendously, but yeah,
that that has to happen, but it just you know,
it's not We're not quite there yet.
Speaker 1 (31:11):
So there you have it. You can build a quantum
computer in your garage right now for about a million dollars,
although for that money right now, you could only put
about twenty cubits on it, which is about as sophisticated
as an abocus, although this case would be a quantum ebicus. Right.
The last thing we'll talk about is why quantum computers
(31:31):
are so hard to make. If they can break any
encryption on the planet, or potentially let us simulate new
chemicals and materials, why haven't we done it? What is
so hard about making a quantum computer? Here's Oscar explaining it.
Speaker 3 (31:45):
Probably the thing that makes it most difficult, and maybe
it's the most relevant to talk about, is that let's
say you want to do a computation with a quantum computer,
and you want to describe it by a certain number
of particles, and you want to use those particles to
do your quantum simulation. Then you need to be able
to control those particles right, to manipulate them to do
the computation you want. But if those particles interact with
(32:07):
the environment, then part of the information that you wanted
to control or manipulate will actually evolve and become connected to.
Speaker 2 (32:15):
These other particles.
Speaker 3 (32:16):
And that's the really tricky problem is how do I
control tiny little quantum particles with my grubby little hands,
so to speak. So I have to be able to
send in these control signals to and manipulate these quantum particles,
but I can't let in any other parts of the
environment in the same time, and so it becomes a
really hard problem to sort of shield the system you're
(32:39):
trying to use to do this computation, but then also
allow yourself these control knobs.
Speaker 1 (32:44):
Is it like a question of purity to.
Speaker 3 (32:46):
Some degree, yes, Like the properties electron have to be
just that electron, and they interact with other things that
you're not able to control, you lose the information.
Speaker 2 (32:56):
All right.
Speaker 1 (32:57):
So the reason that quantum computers are so hard to
make and run basically goes back to Schrodinger's cat. Might
have heard of this analogy when people are talking about
quantum things, And the idea is that if I take
a cat and I put it inside a box, and
I also put in the box a quantum particle that
might kill the cat. Then when I close the box,
(33:19):
eventually the cat becomes both alive and dead at the
same time. And that's because when I close the box,
the quantumness of that killer particle basically extends to the
cat itself. Now, a quantum computer is basically like taking
a whole bunch of those boxes with cats that are
alive and dead at the same time, and it tries
(33:41):
to do math with them. And because all those cats
are in that magical quantum state of being two different
things at the same time, alive and dead, then you
can do some really powerful computations with them, like multiply
a whole bunch of numbers all at the same time.
But as soon as anyone takes a peek inside one
of those boxes and the whole thing collapses. As soon
(34:02):
as you open one box and you see whether the
cat is alive or dead, then that box loses its
quantum magic, and all the other boxes that are talking
to it will also lose their quantum magic. So the
reason you need to build giant refrigerators and keep these
computers in an almost perfect vacuum with perfect coldness is
to protect them from any random bit of motion or
(34:24):
energy from essentially peeking inside your quantum boxes, because if
that happens, the whole thing collapses and stops working. And
this problem only gets worse as you make the computers
bigger and more complicated. But people like Oscar are getting
better and better at it. Well, that was great, that
was awesome. I guess just the last question, what is
(34:45):
the current state of the art in quantum computers?
Speaker 3 (34:48):
Yeah, so I think that if you can look at
this on I would say three axis, so you can
ask how many physical cubits can I make in.
Speaker 1 (34:55):
Control right now?
Speaker 2 (34:56):
Right?
Speaker 1 (34:56):
What's the highest number of somebody that has been So.
Speaker 3 (34:58):
If you just said I just want to be to
control this many cubits, it's a few hundred. And people
have made systems of more than a few thousand, but
maybe not controlled all of them simultaneously. But people have
definitely made a few hundred and controlled them. So we're
getting to that level. And you might say, well, okay,
put that in context, and if we could control them
(35:19):
with high enough fidelity and not make errors, we would
be at the point where we could actually start to
access and solve problems of practical utility better than we
think other computers can, like we could answer some of
these questions about how electrons interacted materials, like small toy problems,
but still useful.
Speaker 1 (35:35):
So like, if I have a thousand cubits working, yeah,
what kinds of passwords can I break? Right now?
Speaker 2 (35:40):
Yeah?
Speaker 3 (35:41):
So, like the number of bits and an RSA key
is like a few thousand, So if I had a
few thousand cubits, I could crack RSA a.
Speaker 1 (35:49):
Few thousand, and we're at one thousand now. Yeah, so
right now we can maybe crack simple passwords.
Speaker 3 (35:55):
Like yeah, surely that's right, shorter short of ones that
we can already do classically, So probably not useful, but
we're within striking. But the bigger problem is that we
can't do those calculations because our calculations are too air prone.
Speaker 2 (36:06):
Then we need to add the air correction.
Speaker 1 (36:08):
Okay, that's the other that's the root axs.
Speaker 3 (36:10):
And that's adding redundancy, and so really think about it this.
I need to not have just a few thousand physical cubits,
but I may need a few million because the redundancy
factor is pretty large right now, Like if my hardware
had no errors, I wouldn't need to do any air
correction and the redundancy factors one. But I do have errors,
and the errors we have right now require about another
(36:30):
factor of one thousand overhead a thousand cubits multiple thousands
of times, so it'd be a thousand times of thousand,
which is a million. If I need a thousand cubits
to do computations with, I have to multiply that by
one thousand, and that gives me how many physical cubits
I need to represent?
Speaker 2 (36:46):
Oh wow, So.
Speaker 3 (36:47):
That's why I'm saying we probably needed like a million
physical cubits. So that's what people are doing right now.
The fact is that we can actually build and control
on order a few hundred one thousand cubits is amazing, right,
that's huge progress.
Speaker 1 (36:58):
Like ten years ago it was z there are cubits.
Speaker 3 (37:00):
I would say we became masters of the individual cubit
so to speak. Maybe even in two thousand we're really
really good at that. It was very hard to first
even figure out, like to control a single cubit. But
since then we've been already growing small cubit systems and
improving how the interacting in the gates that we can implement.
There was a recent result where scientists at Google showed
(37:21):
that their processor would require ten twenty years for a
classic computer to simulate what they've done the processor. You know,
our own team hit Amazon. We focused on a slightly
different hardware implementation that potentially has an ability to reduce
the hardware overhead by factors on the order five to ten,
which could be very important. So, even though it doesn't
(37:43):
have a practical application yet, it's clear like there's a
big difference in the power of what these things can do.
There are a set of problems that the class computers
are just not going to be good at, and there's
going to be a set of things that quantic computers
can do that classical ones cannot mimic. And if you're
watching this as a sort of an interested techy observer
and look looking for a turning point or a tipping point,
I'd be watching for how these air rates go down,
(38:04):
how efficient air correction is in these sort of one
hundred two thousand cubit systems over the next few years.
Speaker 1 (38:10):
Very cool, Well, thank you so much, Oscar. That was fantastic.
Speaker 3 (38:14):
Yeah, I hope we got into enough of the detail
where it's understandable enough. It is definitely a difficult subject
and there's a lot of hype around it. Even for me,
it's very hard to read the news and to decipher
what is really an advance of what isn't. And I'm
deep in the field, so I can only imagine for
others that read about it.
Speaker 2 (38:31):
Very cool, right, all right?
Speaker 1 (38:33):
Thanks a lot, yep, and that is how a quantum
computer works. Thanks for going on this field trip with me.
I hope you enjoyed that. See you next time. You've
been listening to Science Stuff. Production of iHeartRadio written and
produced by me or Hitchm executive producer Jerry Rowland, an
audio engineer and mixer Casey peckrom and you can follow
(38:55):
me on social media. Just search for PhD comics and
the name of your favorite Be sure to subscribe to
Sign Stuff on the iHeartRadio app, Apple Podcasts, or wherever
you get your podcasts, and please tell your friends We'll
be back next Wednesday with another episode.
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