Published: March 25, 2021

In this episode of Buff Innovator Insights, we meet Dr. Jun Ye, director of the CUbit Quantum Initiative. We’ll talk with Dr. Ye about his formative years in China, his transformation into a leading researcher in the US, and how his work is helping to realize the vast potential of quantum science and technology. 

Terri Fiez

I'm your host Terri Fiez, Vice Chancellor for Research and Innovation at the University of Colorado Boulder. And welcome to Buff Innovator Insights. The Buff Innovator Insights podcast is a behind-the-curtain look at some of the most innovative, groundbreaking ideas in the world. Even better. It's an up-close and personal introduction to the people behind the innovations. Today, I'm delighted to introduce you to Dr. Jun Ye, who explores the frontiers of light matter interactions to help better understand the universe and to turn that knowledge into technologies to make our lives better. Dr. Ye is a fellow of the National Institute of Standards and Technology or NIST, a fellow of JILA, which is a joint research Institute between NIST and CU Boulder, and a professor adjoint of physics at JILA and CU Boulder. He is also the director of the CUbit Quantum Initiative that coordinates quantum activities at CU Boulder.

His research group builds on and advances precision measurement, ultra-cold atoms and molecules, quantum metrology, and ultrafast science and quantum control. Dr. Ye is widely known for his work with atomic clocks, and in particular for building the most precise clock ever created. He is also regularly named as a Thomson Reuters highly cited researcher, reflecting his broad and enduring influence on other scientists and his field.

Today we'll learn about how he grew up in a small town in China near the end of the Cultural Revolution and eventually traveled to the US to study physics, how his education and training took him to New Mexico and California before putting down roots in CU Boulder, where he now oversees one of the world's leading quantum science and technology hubs, how quantum science and technology works, why advancing quantum science is such a priority for the United States, and how quantum advances will change technology and impact people around the world. He's not just a top scientist. He's also a fascinating person. Let's meet Dr. Jun Ye.

Jun, I'm really looking forward to our conversation today. Thank you so much for joining us and sharing about your life and the work that you've done. Let's just go ahead and get started. You grew up in China. And when you were young, very young, it was still during the time of the Cultural Revolution. What was it like when you were young in China?

Jun Ye

Thank you, Terri. Thank you for inviting me for this conversation. Yeah. I grew up in a small city, about 200 kilometers south of Shanghai. The town was traditionally well-off. So my childhood life was relatively rich. It was good. But life was very, very simple then. No household appliances whatsoever. I lived mostly with my grandma, who was actually illiterate. And yet, the first gift that I remembered from her was a pencil and notepad. Before I even went to kindergarten, she lost her husband in World War II and raised four children on her own.

Terri Fiez

That's really remarkable. And so as you grew up, did you live separately from both your mother and father?

Jun Ye

Yes. Both of my parents worked. And they were both college graduates, which was not very common at that time. My mom was a scientist on agriculture and environment, required to travel. My dad attended a naval academy and served in the Navy till I was six. And I had actually naughty childhood. So my mom used to tell me, "A less well-equipped bird should fly first." She wanted me to work hard. And my dad used to tell me, "No knowledge is yours until you can say it in your own words." And those are really useful statements. I use them actually with my graduate students today, even.

Terri Fiez

That's amazing. Now about the time you were about eight years old, Chairman Mao died, and the Gang of Four were arrested, which ended the Cultural Revolution. What did that mean for China at that time?

Jun Ye

As a small kid, I remember two things changed nearly overnight. First, people's lives improved drastically. Refrigerators, stereos, washing machines, et cetera, started to come in homes. Second, going to college suddenly became really fashionable. Teachers and scientists regained respect lost during the Cultural Revolution, and people waited in long lines outside of bookstores just to buy a new book. And that was really something that I actually think inspiring, even though the life was just simple and improving at the time.

Terri Fiez

So when you bring up waiting in line to get books, what were your favorite subjects in school and also outside activities?

Jun Ye

Yeah. I actually liked very much traditional literature and poetry, even dating back a couple of thousand years. And I enjoyed solving lots of math problems. I used to go to bookstore to buy math problems. And I was... I would say we were fortunate to have a great high school physics teacher. She was really into getting us excited on experiments. She encouraged me to take part in our national high school physics competition. And that really triggered my strong interest in physics. Because of that, which I did reasonably well in that competition, there was a talent scouting team coming to our high and recruited me into an elite university, Shanghai Jiao Tong University, bypassing college entrance exams. So I consider myself fortunate.

Terri Fiez

Well, they must have recognized the talent that you had and it's proven out over the years. So they were smart. You talked about demonstrating during your college years. What were you demonstrating for and was it safe?

Jun Ye

Yes. Our generation of young students at the time thought much about the rapid social changes happening right in front of us. As I was saying earlier, things just were changing really fast. It's the same people. And yet suddenly, the life is changing in a drastic way. So in college, we went onto streets a couple of times, I remember, to demonstrate for social and political reforms. Mostly it was quite safe, actually. I stayed in a city in Shanghai and it was all quite safe, although I was recommended once by my professor.

Terri Fiez

Yeah. So going back to that then, so you were being really active in China. And then you made a decision to go to the United States to study physics. What changed and why did you decide to do that?

Jun Ye

Yeah. So growing up in the '80s, when China was just opening up, we really experienced a great influx of US influences from Superman to Star Wars, from John Denver to Michael Jackson, from images of San Francisco to New York City. It was all very fascinating. And at this time, US was just a romantic symbol for us. It's the most scientifically advanced society. As a physics student in college, we started to read a lot of literature, scientific literature from the US. So when I was disappointed with the slowness of social changes in 1989, I decided to come to the US.

Terri Fiez

So let's go ahead and transition now into your graduate school and building your professional career. So you decide to come to the United States. And I always think of coming to America for the first time. Were your parents supportive when you were going to leave China to come to United States?

Jun Ye

Yes, they were supportive. They of course were... It was hard for them to say goodbye for me to travel because I've never traveled that far before, but they were supportive that it's an opportunity for me to learn new things. And when I first left China, my intention was, well, I want to explore this new place and we'll see how things go. I may or may not return to China. And yet I myself was, of course, very excited to explore a new world.

Terri Fiez

So tell us about your graduate experiences. You came to University of New Mexico, and then to CU Boulder. Tell us about that experience. And what was it like for you initially as a Chinese with American roommates, and what did you experience?

Jun Ye

The reason I went to New Mexico in Albuquerque was because of a visiting scholar at my home university in Shanghai. He was an amazing quantum optician, [Marlon Skali]. So I wanted to learn theoretical quantum optics from Marlon. That's why I went there. And at UNM, I had a great time working with three of my roommates who are all American students at the same age of myself. And we had a great social bonding. I learned all kinds of different English slangs and went to bars, did a little bit of a drinking. I was above the age. But it was really fun to get a [inaudible] into the society there with my student buddies and so on, but also was learning hard in physics. I became really interested in atomic physics and the precision laser experiments.

And that's when the first time CU Boulder came into focus, because I've read about JILA and I'd read about John Hall. Professor John Hall, we call him John, nickname. And I'd remember, was so excited about the idea of want to work for John [inaudible] to Boulder from Albuquerque and just to ask John whether he would take me on as a graduate student before I was admitted. And Jan's first response when he first met me was, "Well, you certainly are a brave boy," but I would never had imagined at that time that he would teach me so much about trusting your own hands and building the best instruments you can in the world. This was a complete transformation of my life, basically from a reader and a thinker to a doer.

Terri Fiez

That's really exciting and pretty amazing. I'm sure he remembers that first visit by you like it was yesterday. For those of you who don't know, John Hall is a legend. He was at JILA prior to Jun being there, as he just mentioned. And in 2005, he won the Nobel Prize in physics. And so he's truly a legend on both the CU campus and with NIST.

You have a unique position today at CU Boulder and the National Institute of Standards and Technology. Can you describe what that is?

Jun Ye

Yes. After my PhD, I took a two-year postdoc work at Caltech, and then I was hired back as a faculty member at JILA. This is at joint institute between the University of Colorado and the National Institute of Standards and Technology.

If there is one perfect marriage in the world, the CU-NIST marriage is it. It was a strong collaborative culture. We research fundamental physics, develop new technology while keeping a focus on measurement science for NIST and for the nation. JILA students are simply among the very best in the world.

Terri Fiez

At any one time, how many graduate students and postdocs are working in your laboratory?

Jun Ye

I have on average for the past 20 years or so, I have about a dozen graduate students, PhD students, and about eight postdocs at one time. And I feel that we challenge each other, we meaning I'm part of them, kind of like a big family. We challenge each other every day intellectually, and we support our lab work collectively.

Terri Fiez

Sounds fun. I think I'd like to work there. Well, let's talk a little bit about the work that you do. We hear the term quantum in the news, and that's what you've studied in the area that you work in. Can you tell us in lay terms what this means and why should we care?

Jun Ye

Yeah. Superposition is probably a phrase that stands out in quantum. You probably have heard of it. It's a concept that something can exist in multiple physical states at once. All we do is to harvest this holistic view of matter for new technologies such as computers, lasers, clocks, magnetic resonance imaging for health. What is gaining steam right now is to work with multiple quantum systems and have them develop joint superpositions.

Superposition is weird enough. Joint superposition is just weirder. And yet, it's more powerful. It's like developing super harmonious relations with all of your friends. And then we all benefit from each other. This sounds almost like the true meaning of life, isn't it?

Terri Fiez

Yeah. It's that simple, huh? Well, just to follow on with that, you're very much an experimentalist, as you talked about. Do with your hands. But you have a very deep theoretical background from your New Mexico time and to your time in China. Tell us what your graduate students do and how you work with them.

Jun Ye

That's an excellent question. When people think about quantum, they will think, "Oh, that's so exotic. That's something I don't experience every day. How do you deal with it?" Well, when you walk into our lab, what first you'll see is zillions and billions of a [mirror mounts] sitting on that optical table. And that's because we use lasers. We use light to communicate with atoms. That's where they open up their soul, their heart to talk to us, what time it is. And so what we build really is a lot of classical technologies to tame these atoms and molecules, to teach them how to cool down, how to remove their entropies, how to become a team worker, how to load yourselves into traps made out of laser light. They start to behave like quantum systems. And then we tease out that quantum information out of these atoms.

Terri Fiez

So I would like to transition to talking about you as a leader in the field and that evolution that you've had over the last decade or two. You're currently leading the new effort funded by the National Science Foundation under the Quantum Leap Challenge Institute, which is called Q-SEnSE. Tell us what you hope to achieve in the next 5 to 10 years through this new institute.

Jun Ye

Well, our goals are really to take advantage of the superposition that talked about, joint superpositions, to realize quantum speed up for making discoveries in fundamental science, developing engineered quantum systems and technologies or practical applications, training a young generation of leaders in quantum science, really opening a pipeline of workforce that can supply some of the best people to national labs, to academia, to industry.

Terri Fiez

Who are your partners in the center and what role do they play?

Jun Ye

Well, to develop the best quantum sensors, we are teaming up with researchers from Stanford, Oregon on the West Coast to MIT and Harvard on the East Coast. For theory development and educational effort, we are partnering with University of New Mexico and Delaware. For system engineering, we are collaborating with Sandia and the Los Alamos National Labs as well as the MIT Lincoln Lab and the National Institute of Standards and Technology.

In the end, the center is here for students. They build quantum systems. They develop fundamental theory. They initiate collaborations. And we have had meetings where students exchange information among many of our partners. So being at the forefront of research and education, these students will emerge naturally as new leaders in academia, industry, and government labs.

Terri Fiez

So you talked about quantum and students involved in this, and it still seems pretty abstract. Can you give me an example or two of really practical applications of quantum and how it will change our lives in the future?

Jun Ye

Because I'm a clock builder, I can tell you the new generation of atomic clocks very much rely on the quantum mechanics principles, how you isolate atom so that it's free of perturbations to give you the best signals you can to build better and better atomic clocks. Those clocks will help you navigate, help you communicate at a speed, at a precision that you can only imagine from a few years ago to be out of reach.

And the field is moving forward quite rapidly. And we have all heard about quantum computer. In many ways, the capability of harvesting, controlling many quantum particles to work together, many atoms to work together, it's the same technology that will allow you to do speed up for computation. And that's why this whole field is exciting is because the impact is wide-ranging from communication to computing to sensing and so on.

Terri Fiez

So you talked about you build high-precision atomic clocks. Can you give us an example of some of the world records that you've set in your career?

Jun Ye

Yeah. In 2014, our optical atomic clock became the most accurate and the most stable atomic clock in the world. Actually, that was the time where there was a press release from NIST and from CU saying that this clock does not lose one second over the entire age of the universe. And that must be good enough for government work. And that, of course, was a joke, but these new records, however, continue to be set and the reset. That's why the field is so exciting. I can see the field is just moving forward with rapid speed. And also, related to that, over the past two years, we also created the world's first quantum gas of stable molecules where molecular motions now must be described by waves of quantum mechanics instead of thinking of them as just particles. And so this new weirdness is going to be brought into more macroscopic objects like molecules.

Terri Fiez

That's exciting. So thinking back and thinking about your upbringing and then the experiences that you've had throughout your life, how has it influenced you to focus on preparing the next generation, and in that preparation really being an out-of-the-box thinker?

Jun Ye

So my parents taught me to think from other people's perspectives, which I think is very important. My research advisors, they showed me that the most effective way of teaching is through spending time and working together closely with students. If you have an optimistic outlook and can-do attitude, then you work with a group of smart students, it really does make you feel that you can chase almost any scientific dreams that you dare to imagine. That allow you to become out-of-the-box thinker because you feel that I can do it with all my students working together with me.

Terri Fiez

As you think about the next decade or two, what are you optimistic about and what is your hope for the future of your field and the breakthroughs that will be found?

Jun Ye

I think it's a truly exciting time for new discoveries and innovations right now. The quantum technology being developed in centers like ours will provide a better measurement and the thus a deeper understanding of our universe and of our planet. So I can talk about many technical benefits such as having clocks flying in space and it will give us a worldwide time that we can all peacefully use that technology for the whole mankind.

But maybe one aspect, the human touch side, which is I think just as important. I have been a CU faculty member for 21 years, over which time I've mentored over about 100 postdoc scholars and PhD students combined, and many undergraduate students. Many of them are now leading professors, top researchers, industry innovators. I remember one postdoc when he was leaving my group, going back to Israel, he declared, "In this most crowded lab space, all of the jungles of electrical cables in a seeming chaos, we have done so much science together." And this was one of my most proud moments. I feel that, yeah, we deliver these kinds of amazing technologies, and hopefully they will be used for very practical applications in addition to having this fundamental physics pitch. But having people like that turned out and have a real impact to the society all over the world, that hopefully is the legacy of JILA, of CU, of NIST, and myself.

Terri Fiez

That's really inspiring. Thank you, Jun. This has been so fun to talk to you. It's exciting to hear where you started from in China and that experience all the way through where you are today and your vision for really helping to change the world and bring it closer together. If not geographically, at least scientifically. So thank you for the time today and all the best as you pursue your science.

Jun Ye

Well, Terri, I want to thank you for this conversation, but also for your leadership and the support at the university. I know you are a true leader. Thank you.

Terri Fiez

That was Dr. Jun Ye, fellow of NIST and JILA and professor adjoint of physics at CU Boulder. It was so interesting to learn about his upbringing in China, his education and training in the US, and how his research and innovation are helping to realize the vast potential of quantum science and technology. You can learn more about Dr. Ye and CU Boulder's CUbit Quantum Initiative at colorado.edu/initiative/cubit. For more Buff Innovator Insights, podcasts episodes, and to join our mailing list, go to colorado.edu/rio/podcast. I'm your host and Vice Chancellor for Research and Innovation at CU Boulder, Terri Fiez. It's been a pleasure to be with you. Innovation is for everyone. We can all make the world a more interesting and better place. Sometimes we just need a spark. We'll see you next time.