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February 8, 2023

Q&A: UW researcher discusses future of quantum research

In a world abuzz with smartphones, tablets, 5G and Siri, there are whispers of something new over the horizon — and it isn’t artificial intelligence!

A growing field of research seeks to develop technologies built directly on the seemingly strange and contradictory rules of quantum mechanics. These principles underlie the behavior of atoms and everything comprised of atoms, including people. But these rules are only apparent at very small scales. Researchers across the globe are constructing rudimentary quantum computers, which could perform computational tasks that the “classical” computers in our pockets and on our desks simply could not.

To help transform these quantum whispers into a chorus, scientists at the University of Washington are pursuing multiple quantum research projects spanning from creating materials with never-before-seen physical properties to studying the “quantum bits” — or qubits (pronounced “kyu-bits”) — that make quantum computing possible.

With their research group in the Department of Physics and the Department of Electrical & Computer Engineering, UW Professor Kai-Mei Fu studies the quantum-level properties of crystalline materials for potential applications in electrical and optical quantum technologies. In addition, Fu, who is also a faculty member in the Molecular & Engineering Sciences Institute and the Institute for Nano-engineered Systems, has led efforts to develop a comprehensive graduate curriculum and provide internship opportunities in quantum sciences for students in fields ranging from computer science to chemistry — all toward the goal of forging a quantum-competent workforce.

UW News sat down with Fu to talk about the potential of quantum research, and why it’s so important.

Let’s start with the obvious. What is “quantum?”

Kai-Mei Fu: Originally, “quantum” just meant “discrete.” It referred to the observation that, at really small scales, something can exist only in discrete states. This is different from our everyday experiences. For example, if you start a car and then accelerate, the car “accesses” every speed. It can occupy any position. But when you get down to these really small systems — unusually small — you start to see that every “position” may not be accessible. And similarly, every speed or energy state may not be accessible. Things are “quantized” at this level.

And that’s not the only weird thing that’s going on: At this small scale, not only do things exist in discrete states, but it is possible for things to exist in a combination of two or more different states at once. This is called “superposition,” and that is when the interesting physical phenomena occur.

How is superposition useful in developing quantum technology?

KMF: Well, let’s take quantum computing for example. In the information age of today, a computational “bit” can only exist in one of two possible states: 0 and 1. But with superposition, you could have a qubit that can exist in two different states at the same time. It’s not just that you don’t know which state it’s in. It really is coexisting in two different states. Thus it is possible to compute with many states, in fact exponentially many states, at the same time. With quantum computing and quantum information, the power is in being able to control that superposition.

What are some exciting advancements or applications that could stem from controlling superposition?

KMF: There are four main areas of excitement. My favorite is probably quantum computation. It’s the one that’s furthest out technologically — right now, computation involving just a handful of qubits has been realized — but it’s kind of the big one.

We know that the power of quantum computation will be immense because  superposition is scalable. This means that you would have so much more computational space to utilize, and you could perform computations that our classical computers would need the age of the universe to perform. So, we know that there’s a lot of power in quantum computing. But there’s also a lot of speculation in this field, and questions about how you can harness that power.

Does the University of Washington have a quantum computer?

KMF: It currently does not. We are gathering materials now to construct a quantum processor — the basis of a quantum computer — as part of our educational curriculum in this field.

Besides quantum computing, what other applications are there?

KMF: Another area is sensing for more precise measurements. One example: single-atom crystals that can act as sensors. For my research, I work with atoms arranged into a perfect crystal and then I create “defects” by adding in different types of atoms or taking out one atom in the lattice. The defect acts like an artificial atom and it will react to tiny changes nearby, such as a change in a magnetic field. These changes are normally so small that they would be hard to measure at room temperature, but the artificial atom amplifies the changes into something I can see — sometimes even by eye. For example, some crystals will radiate light when I shine a laser on them. By measuring the light they emit, I can detect a change.

This is so special. I get super excited because we know that all these things are possible in theory, but we’ve just hit the timescale where we’re starting to see real technological applications right now.

That sounds really exciting!

KMF: Another area I’ll mention is quantum simulation. There are a lot of potential applications in this field, such as studying new energy storage systems or figuring out how to make an enzyme better at nitrogen fixation. Essentially these problems require making new materials, but these are complex quantum systems that are hard for classical computers to simulate or predict. But quantum simulation could, and this could be done using a type of quantum computer. The field is expecting a lot of advancement in materials and other areas from quantum simulation.

The final area is quantum communication. When you’re transmitting sensitive information, you can create a key to encrypt it. With quantum encryption you can distribute a key that’s so fundamentally secure that if you have an eavesdropper, they leave a “mark” behind that you can detect.

How big is the field of quantum communication? Is it happening now?

KMF: Well, in the past few years, quantum communication became a prominent topic in government when China demonstrated secure ground-to-satellite communication.

Let’s shift gears a little to talk about quantum in terms of workforce development. You have companies, national labs and universities all pursuing quantum research. Are there any specific challenges for quantum education?

KMF: What we are doing is crafting a common framework — a common language — for education in quantum. Quantum involves many fields, including chemistry, computer science, material science, chemical engineering and theoretical physics. Historically these fields have all had their own approach, their own vocabulary, their own history. At the University of Washington, we’ve launched a core curriculum in quantum for graduate students who want to pursue careers in this field. Through the Northwest Quantum Nexus, we also have partners for internships.

We need more scientists in quantum because this is an exciting time. A lot is changing. There are many questions to answer, too many. Every field in quantum is growing in its own way. In the coming years, this is going to change a lot about how we approach problems — in communication, in software, in medicine and in materials. It will be beyond what we can think about even today.

For more information, contact Fu at kaimeifu@uw.edu.

Tag(s): College of Arts & Sciences • College of Engineering • Department of Electrical & Computer Engineering • Department of Physics • Institute for Nano-Engineered Systems • Kai-Mei Fu • Molecular Engineering & Sciences Institute • Q&A • UW Quantum X

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