Ming Li joined Atom Computing earlier this year as a Senior Neutral Atom Theorist to work on our atomic array quantum computing technology.
Ming earned his doctorate degree in 2014 from the University of Toledo. He has worked in the field of quantum science for more than a decade, as a researcher, assistant research professor, and theorist for hardware technology companies.
We talked with Ming about his role at Atom Computing and how quantum theory contributes to the development of large-scale, fault-tolerant quantum computers.
Tell us about your role at Atom Computing. What does your job as senior neutral atom theorist involve?
As a theorist, I really have three main responsibilities. The first is to help characterize our prototype quantum computer, Phoenix, through the application of quantum theory as well as modeling and simulation. The second is to really find better controls such as designing better pulse shapes, and better calibration routines to really bring out the best of our quantum hardware. These two things really go hand in hand and are focused on improving our existing system. The third part is to help with the next generations of hardware and quantum computing designs and bring qualitative and eventually quantitative system engineering into the process. When you start to design a quantum computer, you only have qualitative guesses on how it will perform but nothing concrete. But once you start iterating on those designs and making incremental improvements, you can incorporate existing knowledge to help determine what the next generation will look like.
What is the difference between what a quantum engineer does versus a quantum theorist?
Quantum engineers are usually in charge of building, operating, and maintaining a quantum computer. They have intimate knowledge of every piece that goes into a quantum computer. The role of a theorist is to help figure out how the quantum computer performs, how to improve it, and what to consider if we are to build a better one. My challenge is to bring all the information we can gather from quantum engineers such as the physical system around a qubit, various noise sources, and system imperfections, then to distill and abstract them to a model that can be simulated to provide understanding to what we are seeing and how we can improve performance. In industry, quantum engineers and quantum theorists need to work together seamlessly. For theorists to thrive, we really need to connect with the quantum engineers to collaboratively discover which components of the quantum computer are most responsible for its performance and how to improve them.
Why is quantum theory important to the development of large-scale quantum computers?
A quantum computer is a device that derives its power from the “quantumness” of the quantum system it tries to harness. Quantum theory tries to formalize our understanding of how that quantum system works - its properties, dynamics, etc. - and enables us to make predictions or generalizations. It helps to establish a quantitative link between things we can control and things we want to control in the quantum system.
When a system is smaller and performance requirements are lower, you can use relatively simple models to establish that link. As the system gets bigger, it also becomes more complex as different parts of the system become more entangled together. Usually, at the same time, the performance requirements for gate operations and fidelities are also higher. This means the link between what we can control and what we want to control becomes more complex and must be understood more accurately. Theory becomes very important because we need better modeling and simulations to find a more effective and efficient way to establish that link.
How are quantum computers advancing the field of quantum science?
The development of quantum computers poses a unique challenge to both engineering’s and physics’ understanding of specific systems. At Atom Computing, for example, we are building atomic array quantum computers based on neutral atoms. We have chosen our quantum platform but that does not mean that in terms of physics we know everything about what we build. As our quantum computer gets bigger, more complex and requires higher fidelities, we need to understand the quantum systems we build better and more quantitatively. That naturally drives research into understanding these systems that could benefit the broader field of quantum science.
Another aspect is that throughout the development of quantum computers many different technologies within the ecosystem also need to advance in order to better control these quantum systems. These updated technologies will improve the tool box of researchers in quantum science to enable better experiments that could potentially unlock more mysteries in the field.
The third part is the promise of quantum computers to better simulate quantum systems such as complex many-body systems. These systems in general are difficult to simulate and become even more so the more complex they are. With classical computers, there is a pretty clear boundary as to where you can go. Beyond that, it becomes harder and harder – and sometimes nearly impossible – to simulate. Because of that, quantum theories on these very complex systems are hard to develop. You can only simulate within that boundary and you try to distill as much knowledge from the simulation as you can for larger systems. The promise of using a quantum computer to better simulate these systems could open the door to gaining a better understanding of these complex systems and advance our knowledge of how the world works.
Why did you join Atom Computing? What excites you most about the company?
What excites me the most at Atom are the potentials and possibilities stemmed from working on neutral atomic array quantum computers. We only just started to chart the path toward scalable quantum computers using neutral atomic arrays. People have studied other modalities of quantum computing, especially ones based on superconducting qubits or trapped-ion qubits, for a fairly long time. There are already established schemes to make these quantum computers work in the NISQ era as well as known hurdles in terms of scalability. Here, I think, we are just starting to see what we can do and to chart a path of where we want to go. To me, that is really exciting.
How did you get into quantum computing? What do you enjoy most about the field?
Like many people who have come to this industry with a physics background, I was lured by the excitement and promise of quantum computers being the ultimate machine to help expand our horizons in a variety of fields in science through quantum simulation. My background before coming to the QC industry is in the more traditional field of quantum theory where I have experienced the limitations of classical simulation first hand. It was often frustrating when we couldn’t advance our understanding of a complex physical system because a simulation is intractable even when we have pulled every trick we had to simplify our model. I hope ultimately through our work at Atom we will be able to push on these boundaries.
Apart from having a strong long-term motivation for working in the field of QC, I also enjoy working closely with many other talented people from vastly different backgrounds. For instance, I get to work with experimentalists very closely and I get to learn a lot from them from many stimulating discussions. Also to have them being able to test and verify my theoretical predictions is very rewarding. Another aspect I enjoy about the field of QC stems from the fact that it is such a nascent field especially for neutral atom arrays based QC systems. As I mentioned earlier in why I joined Atom, it is very exciting to be one of the first to chart the path to building a useful quantum computer.
What advice do you have for people who want to work in quantum computing?
To build a scalable fault tolerant quantum computer, we need all the talents we can get because I think it is among the most ambitious scientific and engineering quests in human history. Since the number of people with a QC background is still very limited and QC-focused education programs are just starting to take form, we need to really find ways to attract and utilize talents from different backgrounds. I would encourage anyone interested in quantum computing with a STEM background to talk with someone in the QC industry to see how to get involved. And I think the key, similar to how one would break into many technical fields, is to understand the different technical roles that exist in the QC ecosystem and how they contribute to overall progress in quantum. From there, one could then figure out what preparation is needed given their background. In this sense, I hope some of the questions I answered earlier could be useful for people who are interested in the quantum theorist role here at Atom.