Can we make quantum technology work? | Leo Kouwenhoven | TEDxAmsterdam

Good morning everyone, does anyone recognize the image behind me? What is that computer? In fact, it was a mechanical computer. The computer that Alan Turing used and that helped end World War II. The interesting thing is that here the wheels spin and by registering clicks and non-clicks, they could break encrypted messages, so it is a mechanical movement that can actually do some calculations for us. Now we use, of course, electronic computers where the electrical signals and the code for our bits are zeros and ones, but clicks or no clicks or zeros and actually, it's the same principle for encoding information.

There is no difference between the Turing machine and our computers. What's amazing is that, and what's happened in the last 50 or 60 years is that this machine now fits on your wrist and is sold as a SmartWatch. Power to anyone else who has a SmartWatch here. I see some, uh-huh, so you fell in love with the same commercial as me, I guess, but what's smaller and you know, you see the revolution in making things smaller is very visible, but what is it? Perhaps even more surprising is that the underlying principles of the Turing machine are clicks and all clicks and on my SmartWatch it remains the same which has not changed clicks or clicks, zeros or ones.

Some time ago, a very interesting new idea began to become popular. and there really is not a single inventor and in fact it is not really an invention, it is more of a change of perspective and the idea is that nature also calculates, for example, when light hits a green leaf, it induces all kinds of chemistry that in the end The chemical reaction that produces ox, among other things, and the process between light input and oxygen output, can be seen as a calculation. Now why this is an interesting change of perspective, because nature actually calculates much faster and smarter than our computers.

The key ingredient that nature uses is in fact

quantum

mechanics and the beautiful thing about

quantum

mechanics is that you don't have to be a 0 or a 1, you can be 0 and 1 at the same time and this choice of being 0 and 1 at the same time zero ones are used in nature at the same time which sound acceptable but clicks and no clicks at the same time, that is absurd, however people like me have started using these principles of quantum mechanics to build a new computer very powerful it's called a quantum computer and how the quantum computer

work

s and why it's really good that's going to be my story today and first I'll tell you a little bit about myself I grew up in a small town in the Netherlands on a farm and I was actually doing well in high school and they allowed me to go to college, but the only people in my town I knew who had a college degree were our town veterinarian and our priest now becoming a priest was not an option for me, so However, I was going to be a veterinarian and unfortunately my university did not have an entrance exam but a lottery that I lost, so I ended up in my second choice, which was physics, but my roots are still III as the son of a farmer.

I maintain this pragmatic approach and Today, as a professor, if I hear some of my colleagues, you know,

make

very profound theoretical predictions, I think that sounds profound. Can we really do something useful with it? And that is also my attitude to observing quantum mechanics and quantum mechanics is undoubtedly one of the most important. the deepest scientific ideas we have around people like Bohr and Einstein now discovered the deepest principles of quantum mechanics about a hundred years ago and those complex principles are absurd to us humans, but not to small particles like electrons, So what is a small particle? what an electron can do is for example not be confined to a single point in space, it can now occupy different points in space at the same time, how is that possible, it is actually very impossible to explain in words in our language, the best we can do.

What we need to do is simply accept that what is absurd to us is fine for small particles like electrons, so think about this for a moment because it is actually very essential to my story that a single particle, a single object, can be in different places at the same time. Right now we call this superposition superposition and when you accept the superposition, then you can also understand things like chemistry, friends, it's a very simple example, the oxygen molecule, we draw it as two oxygen atoms that are held together by these lines horizontals in the oxygen molecule now.

What do these horizontal lines really mean? Well, they share an electron, but this electron does not stay still in the middle between these two atoms. No, it actually splits, goes into a superposition, and occupies the space around each of these two oxygen atoms. these two parts these two parts of the same electron don't want to be too far apart, it actually keeps the oxygen atoms together and therefore it's a superposition that brings the atoms together in the molecules and, since it's actually our, our body It's made up of molecules so without superposition you know our body would fall apart and without superposition all our molecules would fall apart into loose atoms so superposition is a good thing and you should like it on Facebook since Einstein and Bohr and, In fact, other genius scientists also developed the principles of quantum mechanics.

We have been mainly using formulas, formulas to describe nature as it is given to us, but now, 100 years later, it is time for something new. We now see nature as a processor of information rather than formulas. We use this symbol to describe that there is information. flow in nature and we no longer study nature as it has been given to us, we have actually started designing and building real subprograms of the machines we

make

ourselves and studying how our own designed machines can actually solve quantum problems, so my job has become making qubits instead of a farmer instead I have become a qubit maker or a superposition maker and I want to illustrate that with electrons in boxes, what you see here in the top row are two boxes and one electron in our world, that electron has to choose. can be placed in the left or right box in an information description of the same thing.

What we're saying is that in capital letters when the electrons in the left box I call it a zero bit or if it's in the right box I call it a bit of a one and that's how we encode information in our normal computers, which is a bit of a zero and a little one. Now the special thing that we do in our laboratory in Delft is that we can also do superpositions so that we can take a single electron and put it in both boxes at the same time, something similar to oxygen in the molecule, but now we have boxes that we have made ourselves and also we can control and program so that when the electron is involved in boxes at the same time in a description of the information we say that the system is in a qubit state and the qubit is in a superposition of a zero bit and a one bit at the same time , then we encode that information at the same time now if we have these qubits that we have actually created, a little animation to illustrate how it can be used to speed up calculations and you see here a maze and if we put classical electrons in this library, then the way that electrons actually classically solve this problem to find the way out of the maze is what we see.

Would we try it one way at a time and every time we find, you know it's not a solution, we try again, so we sequentially go through the system until we find the exit, but when we find the exit we know we have the right solution? The quantum electron would split and in parallel in a superposition it takes all the paths at the same time and also reaches the exit, but now much faster and there is the magic of a quantum computer, all these actions, all these different possibilities can be verify in a massive parallel. calculation and finding the answer in a single step that speeds up the calculation so what would we do if we had a quantum computer?

What kind of problems do we really have powering such a super powerful computer well? To answer this question, let's zoom out a little bit and ask ourselves what really are the big challenges that we face on earth the big problem so the many big problems but let's focus on our natural resources here we are we are wasting energy we are wasting materials our climate is also changing rapidly and many people on Earth are not getting the right medicine and these are very big problems that somehow we have to solve and we have to solve them quite soon, at least within the next few decades, to solve those problems we need radically new tools and Nobody doubts that the help of a supercomputer will be of vital importance to really solve these problems and that is why the use of the quantum computer can come.

Now universities where I

work

at a university have begun to develop the foundations of quantum computers for two years. Approximately decades and in recent years also some of the biggest global IT companies have joined this effort and when companies join and invest money, they actually have some specific ideas for the purpose for which they want to use the quantum computer and They have won a little. list of what they say the applications of a quantum computer will be, so it's a list starting with electrical wires with zero energy loss, drug development by solving quantum chemistry problems, predicting material properties for electronics and energy storage, machine learning, optimization problems for robotics, big data management. to sequence genomes and design airplanes, but this list is, of course, not complete.

These are just a few examples and it is impossible to predict. You know what can be done with a new

technology

, so we started an Institute, a new Institute in Delft to really work in a focused way on the development of this quantum computer called Q Tech and in this Institute we manufacture the hardware, so that by using nano

technology

and clean room manufacturing we make electronic chips with a lot of qubits that we can program and by programming these chips we can learn how quantum systems solve problems now, we do it together with electrical engineers and we make these chips that you see here in the last shot and this is an electronic chip that has a lot of qubits and today we can make five to ten cubits on the chip and program it and control it, we think we need another 10 years or so to make circuits that are big enough to actually solve, you know the relevant problems and you have an illustration of how it will develop from there.

So suppose we know that, for example, the largest supercomputer we have in the world today is in the US, it's called Titan, and this computer is actually as big as this concert hall. If I want to make this computer 2 times faster, what I have to do is make it 2 times bigger in two gigs, all if it were a quantum computer. the same starting point, to make it 2 times faster I just have to add a cubit to the supercomputer and a cubit is very small, you can't even see it with the naked eye, so every time you add a qubit to the corne computer it becomes 2 times faster and that is because the computational power of a quantum computer scales as exponential is 2 raised to the power the number of qubits now Exponentials are difficult to understand but let me try to illustrate it with a numerical example and I have to get out of the scenario for this example actually because if I'm a linear machine, if I start giving handshakes to everyone in the audience, then you know it's a linear process and now I need ten steps, in fact, to give ten handshakes and I need two four four more.

I make this linear. I am a classic machine. I guess I could do a superposition and then in ten steps I can shake two to the 10th power, so one thousand twenty-four hands. In the same sequence I would have given a handshake to everyone here in the concert hall and that is the difference between a classical computer or a small section and a quantum computer to everyone in the concert hall, so we are not talking here of some incremental improvement of computing speed in this is really a revolution in information technology, it is a game changer, fun enough and lucky enough in its nature, it actually helps us develop this quantum computer and that takes me back to my leaf in the photosynthesis reaction that occurs between the entry of light where it actually releases electrons in the leaf they have to find a path from their starting point to some specific end point where they can release the oxygen and in the middle There are many different paths that the electron can take to get to the site where it can release the oxygen. oxygen,fortunately the electron can enter a superposition and like in the Liberia problem it can find the final state very quickly and produce oxygen for us very efficiently so that our bodies stay together during the brief oxygen or due to the superposition and that brings me to My take home message is that nature uses quantum mechanics to calculate and we quantum engineers have started to start making programmable quantum computers and help solve some of our earthly problems so I hope that with a common computer we live better lives and be more careful. with our resources on earth thank you very much thank you