Xi Dai, IQC Achievement Award winner discusses superconducting circuits research

Thursday, August 25, 2022
by Kaitlin O'Brien

The Institute for Quantum Computing (IQC) is pleased to announce this year’s recipients of the Institute for Quantum Computing's Achievement Award. This award is given to University of Waterloo graduate students who studied quantum information and have achieved excellence in research. This year's recipients feature three PhD students; Bowen Yang; Shayan Majidy; and Xi Dai.

student standing, wearing a tshirt

Award winner Xi Dai sat down with us to discuss his PhD research with superconducting circuits, the challenges he overcame, and his plans for the future following graduation.

  1.  Congratulations on your Achievement Award Xi. Could you explain what interested you in quantum information and how you ended up studying quantum information science at IQC?

What I like about quantum information science, in particular my field of research, superconducting quantum devices, is its multi-disciplinary nature. This means that there are always new things to learn about, whether it be how to solder, how to communicate with a piece of electronics, or how to quantize the field in a transmission line. It’s just amazing to see that when you put so many different areas of physics together, there is so much you can do with the quantum device.

  1.  What are you researching for your PhD and what is the significance of this research?

My research is about a particular approach to quantum computing, called quantum annealing, which is an algorithm that will allow us to obtain better solutions to hard optimization problems, such as traffic routing and financial portfolio management. There are different hardware platforms that can be used to realize quantum annealing, and our choice is superconducting circuits. My work is mainly about the low-level control and understanding of the hardware, such as developing strategies to characterize and mitigate crosstalk and test how different forms of noise affect the performance of the quantum annealer.

  1.  What challenges did you face during your PhD?

I went through a difficult period while collecting data for my first paper.  My research group and I had all the ideas and methods worked out, all that was left was to write a program that collects all the data in one go, which typically takes a week. However, every time the data collection was complete, I’d find some mistake in my code that makes one whole week worth of data useless. This seemed to happen again and again because there were too many idiosyncrasies in the logic of the code, but I was too afraid to refactor the code. In the end, the data was collected successfully, and was well-recognized after it was published. I was glad that my colleagues were so supportive of me during the time, even though the mistakes I made had caused weeks of delays for the entire team.

  1.  What does winning the IQC Achievement Award mean to you?

A: It is a great honor. I am very grateful for the opportunities that IQC and, in particular, my supervisor Professor Adrian Lupascu, provide me with. Without the support of the team and the collaborators, I wouldn’t have been able to grow so much in these four years.

  1.  What’s next for you in quantum information science?

I am planning to graduate next year and I want to continue doing research about superconducting quantum systems whether that be about building large-scale systems towards fault-tolerant quantum computing, or using a smaller system to explore exotic quantum phenomena.

  1.  Do you have any advice for someone who is thinking about applying to a quantum information program or is interested in learning more about quantum sciences?

Quantum information is still a young field. There is still plenty of room in theory, and experiments, especially in between theory and experiments. IQC is a great place to be for quantum information because of its inter-disciplinary nature, and continuous support