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Interview with Dr. Barry Sanders

Dr. Barry Sanders is interviewed by Denis Farnosov, CEO at ApexQubit,on quantum computing, current state of the technology, types of problems on which scientists are focusing, leaders in the industry, and on building quantum computer at home. This is a text version of the podcast.

Dr. Barry Sanders is Director of the Institute for Quantum Science and Technology at the University of Calgary, Lead Investigator of the Alberta Major Innovation Fund Project on Quantum Technologies, a Thousand Talents Chair at the University of Science and Technology China and a Vajra Visiting Faculty member of the Raman Research Institute in India. He is a Fellow of the Institute of Physics (U.K.), the Optical Society of America, the American Physical Society and the Royal Society of Canada, and a Senior Fellow of the Canadian Institute for Advanced Research and Editor-in-Chief of New Journal of Physics.

Denis Farnosov: Hi everyone, it’s Denis Farnosov here, and welcome to the first ever episode of the Quantum Bit Podcast where we dive into the world of quantum computing. I’m extremely excited because on stage of the show we have Dr.Barry Sanders, Professor in Theoretical Physics, Director of the Institute for Quantum Science and Technology at the University of Calgary. If you love the show please don’t forget to subscribe. So put your hands together for Dr. Barry Sanders! Let’s jump straight right into it. Hi Barry, please tell us a little about yourself.

Dr. Barry Sanders: Hi Denis, I’m really pleased to appear in this broadcast. I work at the interface between quantum physics and computer science. My focus is on how quantum mechanics could radically transform our approach to computing and to secure communication. About myself personally, I’m a dual citizen of both Canada and Australia but think of myself as a global citizen, I’m a member of the world. And I have positions in Calgary in Canada, the University of Science and Technology in China and the Raman Research Institute in India.

Denis Farnosov: Can you please explain to our listeners what is quantum computing?

Dr. Barry Sanders: Sure happy to do so. Let’s begin with computing and then talk about how computing can be quantum. First of all computing is about putting zeroes and ones into a machine that, in turn, gives back a different set of zeroes and ones: the first set of zeroes and ones is the input to the computer, and this first set represents the problem and it can also represent the program. The second set of zeroes and ones is the answer to the computational program. And then we could also get some more which could be the run-time for the program or a bound on the possible error of the output. Quantum computing is really just about computing, we also care about inserting zeroes and ones and getting zeroes and ones in the output. The difference is the machine itself where is computing, as we think of it today, executes logical operations such as AND, OR, NOT, and these operations can be built on the principles of classical (and when I use the word “classical” I mean anything that is not quantum), so it is built on these classical principles. Quantum computing has a completely different engine. Instead of using the logic of AND, OR, NOT, we replace this classical engine by a quantum engine. And in this sense the quantum engine augments these logical operations by allowing wavelike superpositions of computational paths. This sounds very mysterious but it’s also enormously powerful. And this quantum logic allows us to make certain part to solve problems easy such as factorizing numbers. If we could make factorizing numbers become easy we could crack codes and undermine the whole trust in the secure communication infrastructure for e-commerce. However the bad news about that erosion is offset by ideas that we have for making communication also secure. So the answer is that quantum computing is really computing but underpinned by a quantum engine that has a logic that transcends the logic that we have used to thinking about.

Denis Farnosov: And why have you decided to work on this?

Dr. Barry Sanders: Well I’m a physicist and a sucker for hard problems and new ways of thinking. I’ve got lucky when I was young that quantum computing came along, concepts started coming out in the 1980s and breakthrough ideas came around in the 1990s and I was hooked, I’ve started to think a lot about how quantum physics and computer science would intersect. So that’s really the draw of a new field and problems nobody even knew how to pose well that coped me in.

Denis Farnosov: Interesting, and why everything is working so fast on quantum computers?

Dr. Barry Sanders: Ultimately when we are using quantum computer we would like to solve a problem faster, but the quantum computer is not really about how fast it is, it’s identifying problems that could be made easy to solve on the quantum computer and hard to solve on a classical computer. The idea is that if we can find such problems than even if they are slower to solve today, eventually when the problem gets big enough, the quantum computer would be faster. So let me just to be clear, the focus that we have these days is to find problems that would become easy to solve on a quantum computer, and then if it’s easy to solve it would be faster. But a quantum computer itself is not necessarily faster with respect to time of a computer cycle itself.

Denis Farnosov: Right, and what is a current state of the technology today?

Dr. Barry Sanders: The current state of technology is that we have multiple directions. We have hardware and are settering different ways to build a quantum computer, we have different modules of quantum computing and we have different kind of problems that we are exploring. So it’s a very complicated array of different activities, each one promising, but we don’t know which ones are going to work. Let me be more specific. We have different types of approaches to quantum computing such as executing quantum logic gates or making an entanglement measurement or doing adiabatic, or annealing or topological. These different words represent very different approaches to quantum computing and each of them is on different level of maturity when it turns to the action. Some of these quantum computers have thousands of quantum bits and some only have tens of quantum bits. So one can look better than the other. But an approach with thouthands of quantum bits might turn out to not be better than another approach where we have just a few tens of quantum bits. Some are faster and some are slower, some can run thru more logic operations, some can run thru fewer ones, and so the answer to your question is with respect to hardware — the current state is really multidimensional: there are different components and different approaches, all are at different levels. So today we actually have quantum computers that can solve problems using these different methods, but at the moment, in the current state, we do not yet have a quantum computer that provably solve the problem that we can not solve today with classical computing. However over the next five years we have a good reason to believe that we will be able solve problems beyond classical capability. The community is working hard to squeeze the most quantum computing possible out of existing technology, push to more quantum bits and more quantum logic gates and find problems that will demonstrate superior performance on a quantum computer. So the state today is we are trying many different methods and over the next five years we should have a demonstrated superiority of quantum computing in some applications.

Denis Farnosov: How do you think, when should we expect the quantum leap?

Dr. Barry Sanders: By the quantum leap I understand when you say as being the leap to useful quantum computing. And that becomes a hard question, but an excellent question. In fact that leap might have happened already, it could be that with our existing capability with quantum computers it might already show superior performance for quantum computing, we just need to find a right problem to apply. It could be that we will never find one, that is a high risk, high gain aspect in this field when it could take many years before we actually discover a useful problem or we might never find a problem what would demonstrate an advantage, we are hoping otherwise, but it is a risk. And the reason that your question “When the quantum leap will take place?”, the reason it is hard is because we actually have beautiful commercially available quantum computers to play with today, so in this sense the quantum leap has happened. And we do not yet have the problem that shows the quantum advantage in our hands. That could happen tomorrow. So tomorrow could be the quantum leap when we discover that quantum computers are useful. My gut feeling is that we the quantum leap for computing will happen within the coming five years, and maybe sooner.

Denis Farnosov: In your opinion who are leaders in quantum computing today?

Dr. Barry Sanders: The field is really complex and diverse: hardware, software, algorithms, complexity and we have a real wide an array of people and companies to choose from as leaders. Let me just to narrow down the list to just the United States and Canada that I am really familiar. I want to begin by mentioning Canada’s D-Wave quantum computing company, it is almost 20 years old, it is the oldest quantum computing company and they produce a computer with thouthands of qubits, it is commercially available and people can use it. Certainly they deserve credit as a visionary company that commercialized a quantum computing early and one of industrial leaders. Large companies such as IBM, Intel and Google are working with superconducting quantum bits (the same as D-Wave is doing, not the same qubits, but the same superconducting idea) and are doing amazing work in building up the complex technology and building larger and larger quantum computers. Some of these are available on the cloud to play with just as D-Wave’s is. Rigetti is an example of a new fast-growing startup company that focuses on superconducting quantum computing. We have other companies such as Xanadu, PsiQuantum. Xanadu is in Canada, PsiQuantum is in the United States and they work with light. IonQ in the United States and they work with ions or charged atoms. Microsoft is going into the action and they are interested in a different direction that makes a use of topological quantum computing, and they have invested in groups in Europe and Australia to develop that technology. Also Microsoft has become an underspirate leader in a software for quantum computing. Other software companies and startups have appeared such as 1QBit in Canada, Quantum Benchmark in Canada. Quantum Benchmark is addressing issues with an architectural stack — how to make the architecture to work really well. And then we have thought leaders, just a few names in the United States, the people that if they speak we all will wake up and listen to, examples are John Preskill from Caltech, Scott Aaronson from the University of Texas at Austin and Seth Lloyd at the Massachusetts Institute of Technology. Those three are excellent examples of thought leaders who have come up with really creative ideas and their concepts set forward paths to the community.

Denis Farnosov: That’s really interesting, and my last question for today: can we build a quantum computer at home?

Dr. Barry Sanders: A quantum computer is really hard to build. I don’t want to say it’s impossible, but challenging. The laboratories that do this are really expensive, they have a highly sophisticated equipment that require a lot of expertise to use. It takes enormous expertise to create and operate these quantum computers and things like refrigerators that cool to almost absolute zero temperature, laser beams that have to be exclusively aligned, nanofabrication facilities — just enormous expertise is required to build it. In order to operate it once it is built it requires vast training to use and a deep understanding of how it operates, and typically everybody is doing or has done a PhD to be able to operate a quantum computer on site. The conditions of operation, cold temperatures, backing systems are vastly different at home than in a lab. So can we build one at home? It will be a very expensive home to build one, and I don’t think we always can do that, my feeling is that the future of quantum computing is a using on the cloud and not to have inhouse quantum computers.

Denis Farnosov: Well thank you so much Barry for your time and coming to the show. It was a pleasure to chatting with you.

Dr. Barry Sanders: Great pleasure to talk to you.



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