I've been challenged to explain a topic with five levels of increasing complexity.

It's a completely different kind of computing called quantum computing.

Quantum computers approach solving problems in a fundamentally new way.

And we hope that by taking this new approach to computation will be able to start exploring some problems that we can never solve any other way.

Hopefully by the end of today everyone can leave this discussion understanding quantum computing at some level.

What's this?

What do you think that is fancy chandelier?

I think so too.

We jokingly call it the chandelier, that's real gold.

You know, this is a quantum computer.

It's a it's a really special kind of computer.

What does it do?

It calculates things but in a totally different way to how your computer calculates things.

What do you think this is?

Yeah.

You know what your computer thinks that is zero.

This really specific combination of zeros and ones, everything that your computer does, showing you pink panther videos on youtube, calculating things, searching the internet.

It does all of that with a really specific combination of zeros and ones which is crazy, right?

That would be like saying your computer only understands these quarters for each quarter.

You need to tell it that you're gonna use heads tails and you assign it heads or tails.

So I can switch between heads and tails and I can switch the zeros and ones in my computer so that it represents what I wanted to represent like an A and with quantum computers we have new rules, we get to use to, we can actually spin one of our quarters.

So it doesn't have to choose just one or the other.

Can computers help you with your homework?

You're really hard homework.

Yeah, that can, especially if doing your homework involves calculating something or finding, but what if your homework was to discover something totally new?

A lot of those discovery questions are much harder to solve using the computers we have today.

So the reason we're building these kinds of computers is because we think that maybe one day they're going to do a lot of really important things like help us understand nature better.

Maybe help us create new medicines to help people.

What's your favorite kind of computer?

Smartphone, tablet, regular laptop pc?

I've got to go with my iphone.

So what do you do with your iphone social media?

Um use it for your studying, Have you ever run out of space on your iphone all the time?

Me to always when I'm trying to take a photo.

So did you know that there are certain kinds of problems that computers sort of run out of space?

Almost like you're trying to solve the problem and just like how you run out of space on your iphone when you're trying to take a picture, if you're trying to solve the problem, you just run out of space And even if you have the world's biggest supercomputer.

Did you know that can still happen?

So my team is working on building new kinds of computers, altogether?

Ones that operate by a totally different set of rules.

So, do you know what that is?

I have no clue.

It's quantum computer.

What have you ever heard of a quantum computer?

I haven't.

Have you ever heard of the word quantum?

No.

Okay, so quantum mechanics is a branch of science, just like any other branch of science, it's a branch of physics.

It's the study of things that are either really, really small, really, really well isolated and really, really cold.

And this particular branch of science is something we're using to totally reimagine how computing works.

So we're building totally new kinds of computers based on the laws of quantum mechanics?

That's quantum computer is I'm gonna start by telling you about something called superposition.

So, I'm gonna explain it using this giant penny, Is that worth 100 pennies?

I don't know what it's worth, but I can put it face up.

Right, And that's heads, I can put it face down.

Right?

So at any given time point in time, if I ask you is my Penny?

Heads or tails?

Probably you can answer it.

Right.

Yeah, Okay, But what if I spin the Penny.

So let's do it.

Okay, so while it's spinning, is that heads or tails?

While it's spinning?

Oh, I wouldn't know it's sort of it's sort of a combination of heads and tails, Right, would you say so.

Superposition Is this idea that my penny is not just either heads or tails, It's in this state which is a combination of heads and tails.

This quantum property is something that we can have in real, real physical objects in the world.

So that superposition.

And the second thing that we'll talk about is called entanglement.

So now I'm gonna give you a penny, wow.

When we use the word entangled in everyday language, what do we mean that something is intertwined or exactly that there's two things that are connected in some way and usually we can separate them again.

Your hair is tangled or whatever, you can un entangle it, right?

But in the quantum world when we entangle things, they're really now connected, it's much much harder to separate them again.

So using the same analogy, we spin our pennies and eventually eventually they both stopped, right?

And when they stop, it's either heads or tails.

Right?

So in my case I got tails and you've got heads, you see how they're totally disconnected from each other, right?

Our pennies In the real world.

Now, if our pennies were entangled and we both spun them together, right?

When we stop them, if you measured your penny to be ahead, I would measure my penny to be ahead.

And if you measured your penny to be a tail and measure my penny to be a tails.

If we measured it at exactly the same time we would still find that they were both exactly correlated.

That's crazy.

That's cool.

My God.

The way that we are able to actually see these quantum properties is by making our quantum chips really, really cold.

So that's what this is all about.

Actually this is called a dilution refrigerator and it's a refrigerator.

It does you look like a normal refrigerator, right?

But it's something that we use actually there's usually a case around it to cool our quantum chips down cold enough that we can create super positions and we can entangle cubits and the information isn't lost to the environment.

Like what could those chips to be used to do?

So one of the things that we're trying to use quantum computers to do is simulating chemical bonding.

Use a quantum system to model a quantum system.

Yeah, I mean I'm definitely gonna impress all my friends when I tell them about this, they're gonna be like quantum.

What?

So what do you think that thing is is it some sort of conductor circuit that is a really good guess.

There's parts of that that are definitely about conducting, this is the inside of a quantum computer.

Oh wow.

Yeah this whole infrastructure is all about creating levels that get progressively colder as you go from top to bottom down to the quantum chip which is how we actually control the state of the Cupids.

Oh wow.

So when you say colder you mean like physically colder?

Like physically colder.

So room temperature is 300 kelvin as you get down all the way to the bottom of the fridge.

It's that 10 million kelvin.

Oh wow, Amanda, what do you study?

So I'm studying computer science currently a sophomore.

And the track that I'm in is the intelligent systems track machine learning artificial intelligence.

You ever heard of quantum computing?

From my understanding with a quantum computer rather than using transistors is using spins, you can have superposition of spins, so different states more combinations means more memory.

So that's pretty good.

So you mentioned superposition but you can also use other quantum properties like entanglement entanglement.

I have not.

Okay, so it's this idea that you have two objects and when you entangle them together they become connected and then there sort of permanently connected to each other and they behave in ways that are sort of a system now.

So superposition is one quantum property that we use.

Entanglement is another quantum property.

And a third is interference.

How much you know about interference?

Not much.

Okay, so how do noise canceling headphones work?

They read like wave, ambient wavelength and then produce like the opposite one to cancel out they create interference.

So you can have constructive interfere and you can have destructive interference.

You have constructive interference of amplitudes, wave amplitudes that add to the signal gets larger.

And if you have destructive interference, The amplitudes cancel by using a property like interference.

We can control quantum states and amplify the kinds of signals that are towards the right answer and then cancel the types of signals that are leading to the wrong answer.

So given that you know that we're trying to use superposition entanglement and interference for computation, how do you think we build these computers?

I have no idea.

So step one is you need to be able to have an object or physical device.

We call it a cubit or quantum bit that can actually handle those things can actually be put into superposition of states, you know, to cube.

It states that you can physically entangled with each other.

That's not really trivial.

Right?

And things in our classical world, you can't really entangle things in our classical world so easily.

We need to use devices where they can they can support a quantum state and we can manipulate that quantum state, atoms ions and in our case superconducting qubits, we make cubits out of superconducting materials.

But as like a programmer, how would quantum computing affect a different way of writing a program?

It's a perfect question.

I mean it's very early for quantum computing but we're building assembly languages.

We're building layers of abstraction that are gonna get you to a point as a programmer where you can interchangeably be programming something the way that you already do and then make calls to a quantum computer so that you can bring it in when it makes sense.

We're not envisioning quantum computers completely replacing classical computers anytime soon?

We think that quantum computing is going to be used to accelerate the kinds of things that are really hard for classical.

So what exactly are some of those problems simulating nature is something that's really hard because we take something like modeling atomic bonding and electronic orbital overlap.

Instead of now writing out a giant simulation over many terms, you try and actually mimic the system, you're trying to simulate directly on a quantum computer which we can do for chemistry.

And we're looking at ways of doing that for other types of things.

There's a lot of exciting research right now on machine learning trying to use quantum systems to accelerate machine learning problems.

So would it be like in five years or 10 years that I would be able to have one of these sitting in my laptop just in my dorm?

I don't think you're going to have one in your dorm room anytime soon, but you'll have access to one.

There's three free quantum computers that are all sitting in this lab here that anyone in the world can access through the cloud.

Okay, so quantum computing creates new possibilities and new ways to approach problems that classical computers have difficulty doing.

Couldn't have said it better myself.

So I'm a first year master student and I'm studying machine learning.

So it's in the computer science department but it mixes computer science with math and probability and statistics.

So have you come up upon any limits to machine learning?

Certainly depending on the complexity of your model then computer.

One thing I have colleagues here that you can take up two weeks to train certain neural networks and actually machine learning is one research direction where we're really hoping that we're going to find key parts of the machine learning computation that can be sped up using quantum computing.

It's exciting.

So in the classical computer, you know, you have all sorts of logical gates that perform operations and they change an input to some sort of output.

But I guess it's not immediately obvious how you do that with quantum computers.

If you think about even just classical information like this right at the end of the day when you store a bit in your hard drive, there's a magnetic domain and you have a magnetic polarization, right?

You can change the magnetization to be pointing up or pointing down.

Right?

Quantum systems were still manipulating a device and changing the quantum state of that device.

You can imagine if it's a spin that you can have spin up and spin down.

But you can also, if you isolate it enough, you can have a superposition of up and down.

So what we do when we try to solve problems with a quantum computer is we encode part of the problem we're trying to solve into a complex quantum state and then we manipulate that state to drive it towards what will eventually represent the solution.

How do we actually encode it to start with?

Yeah, that's a really good question.

This actually is a model of the inside of one of our quantum computers.

So you need a chip with cubits.

Each cubit is a carrier of quantum information and the way we control the state of that cube, it is using microwave pulses.

You send them all the way down these cables and we've calibrated these microwave pulses so that we know exactly this kind of pulse with this free this duration will put the cube it into superposition or will flip the state of the cubit from 0 to 1.

Or if we apply a microwave pulse between two cubits, we can entangle them.

Yes, exactly.

Also through microwave signals, the key is to come up with algorithms where the result is deterministic, interesting.

So what do those algorithms look like?

There's sort of two main classes of quantum algorithms.

There's algorithms with which were developed for decades.

Things like Shore's algorithm, which is for factoring Grover's algorithm for unstructured search.