Women Pushing the Limits of Quantum Frontiers: Ziwei Qiu

Becoming a scientist isn’t an easy path. Studying physics, or any other hard science requires many sleepless nights, long days in the lab, and the passion to keep pushing forward. Our next speaker profile highlights the fact that while studying science requires hard work, it is all well worth it.

Introducing: Ziwei Qiu, Ph.D. Candidate in Applied Physics at Harvard University at the Yacoby Group.

Ziwei is a graduate student at Harvard University. She is an experimentalist working on developing quantum sensing techniques in Amir Yacoby’s group. Prior to this, she obtained her Bachelor’s degree in physics from Peking University. Her Ph.D. research focuses on using spin defects in diamond scanning tips to detect a variety of signals, with high precision and sensitivity at nanoscale resolution. This technique has promising applications in probing condensed matter systems.

Initially, what attracted you to physics? Can you tell us a little about what compelled you to choose physics as a major?

I became interested in physics very early on, probably in high school. I was amazed at how physics is able to give very clean and beautiful explanations for intriguing phenomenons in nature. I also really enjoy learning, so I was interested in learning how to solve complicated problems. When I entered college, I chose physics as my major based on two main reasons:

First, I like that you can learn so much through physics. You learn how the world works at a very low level and then you dive deep into learning the underlying principles of seemingly counterintuitive phenomena. Along the way, you develop your own intuition and philosophies about the world. I really like that studying physics gives me a lifelong purpose and drive to continue learning.

A second reason is that while learning physics, you also develop other useful skills, that not only benefit your studies but also whatever you decide to do in your career later on. For example, by learning physics, you learn how to model a complicated problem by doing approximation or by analyzing higher-order effects and distilling the essential information. I also like that you learn how to combine theory and experiments. Besides being fun for me to learn, physics is also very useful and interesting. So I didn’t hesitate when I chose physics as my major.

How did you decide between focusing on experimental vs theoretical physics?

It wasn’t a hard decision for me, actually. Even as a kid, I liked to use my hands to build things; I would disassemble a radio and try to put it back together. So it didn’t take long for me to choose to be an experimentalist. Since you still spend time studying theory as an experimentalist, it wasn’t an all-or-nothing decision.

What was your experience when you were first starting out in college?

Physics is a hardcore subject so I was always on a very steep learning curve. It took some time to adjust, but I really enjoyed it because every day, I’m learning something new. You also have to work really hard and practice a lot to get a good understanding of the concepts, especially when it comes to more advanced courses. But all of the effort I put in eventually paid off because once I was more comfortable with the concepts, I really enjoyed learning more. It’s still a challenge, but at the same time, it’s very rewarding and enjoyable.

What is your current research focus? And what does a typical workday look like for you?

I’m working in Amir Yacoby’s lab on developing quantum sensing techniques using state defects in diamond. So the state defect is called a nitrogen-vacancy center. It has an electron speed associated with it, and amazingly at this little speed, it has a very long coherence time even at room temperature. Because of this property, we can use it for highly sensitive detection of a variety of signals, such as magnetic or electric fields.

So we make material samples, like graphene or a magnetic sample, which has an interesting electric or magnetic field of distribution. Then, we bring a nitrogen-vacancy center in diamond, close to this sample, and then it will interact with the magnetic electric fields from the sample. With quantum control sequences, we can measure this signal. By scanning over the sample, you can create an image and map out how the signal is distributed in the sample. And from there, you’re able to understand the underlying physics in the material.

In terms of a typical day, I don’t think there even is a very typical workday. My schedule varies a lot, and it depends on what stage I’m at in my project.

What are the stages of working on a project?

In the very beginning, you need to brainstorm ideas. So you read a lot of literature and talk with colleagues to come up with ideas for experiments. I really enjoy this part, since you have so much freedom. There are so many possibilities. Once you have an idea for a project, for example, if you want to make a device by yourself, then during this stage, you may spend a lot of time in the cleanroom designing macroscopic patterns and creating nanoscale devices.

And the success rate of making a device isn’t usually high, so you might need to try again and again. Once the device is built, you need to spend time testing all the instruments and the hardware and writing automation software to control it. So you typically spend a lot of time debugging and recalibrating before running real experiments because the success of the whole experiment really depends on the success of every little step.

Once your setup is ready for experiments, then you would load in your sample, and basically babysit your experiment to make sure nothing weird happens. Then you run experiments that you wrote in advance and make sure that everything is running as expected. Usually, the software can do automatic analysis, and then based on that real-time data you can decide your next step, and whether there’s something new to explore or to continue with your original plan. After you’ve collected enough data, then you will move your focus to data analysis.

This stage is very exciting. You compare your results with your theoretical predictions. And you can collaborate with some theorists who may have done simulations of the calculation, and compare whether they are consistent with your results, or you can do the theoretical analysis by yourself. And if your results are consistent, that’s great, and if they’re not that’s even better. It means that you observed something unexpected, so you can dive deeper into it and possibly discover something new. So if things are consistent and conclusive you can wrap up and conclude your experiment, and ideally, you can write a paper out of it. Or if you discover something new, you can continue to design new experiments to further confirm your hypothesis.

And this sounds very sequential, but in reality, it’s a very iterative, non-linear process. So you might jump back and forth to a different stage depending on your results.

How significant have role models and mentors been for you? And is there anyone specific you look up to?

Very significant. Currently, during my Ph.D., I’ve really gotten a lot of support from my advisor, Amir. I really appreciate that when I come to him with difficulties or challenges in my experiments, he not only looks at the bigger picture but also cares about the details. So when I encounter problems or technical challenges, he will actually sit down with me and analyze every component to see what could have gone wrong. And it’s great to feel that when you encounter challenges or something unexpected, you don’t feel like you’re working alone; you can discuss it with your advisor and your coworkers. Knowing that they are always willing to help is really encouraging, even when things aren’t going smoothly.

When I was a kid, I read a lot of biographies about scientists, like Einstein and Maxwell. So now when I’m doing research in the lab and I run into challenges or problems, I think about how those physics giants would have felt or what they might have done during similar moments. So I really gain a lot of energy and motivation from thinking about how these big physicists also experienced difficult times. When Einstein first graduated with his Ph.D., he struggled to find a job and ended up working as a patent clerk for a bit. But his dream was still to do physics so he spent a lot of his free time thinking about physics and working on problems, and in the end, it worked out for him.

So I like to keep that in mind and remember that all problems are temporary and will pass; it’s not something I need to spend time worrying about. It’s better to focus on the long term and the ultimate goal of the research.

What are your thoughts on the challenges faced by women working in this field today? And what do you think would help with overcoming those challenges?

From my experience throughout my undergraduate and now graduate school, I definitely feel that the ratio of female students to male students is always quite low. But actually in our lab now, the ratio is pretty balanced; it’s almost 50-50. And as a student, I think there may be a slight psychological challenge, but practically, I don’t think that there is any difference between studying as a woman or a man. So I think the main thing is to not overthink it.

I think seeing more women higher-ups and interacting with them would help with the psychological aspect. Having more opportunities to engage with senior women scientists who have already overcome these challenges in their careers and could share their advice would be really beneficial.

I think ‘imposter syndrome’ is really fitting for what you just described. Have you had experiences with it at any point in your career? What advice would you give to someone feeling this way?

Whenever I’ve transitioned to a new school, I’ve always experienced some form of imposter syndrome in the beginning. With that initial transition period, you have to learn a lot before you feel like you are part of the community. You need to understand the people around you and also learn to speak their language or vernacular. Before that, you might feel like you’ll never fit in, and I’ve felt that way before. But once you start working hard and get through this period, you realize that it wasn’t that you didn’t fit in, you just weren’t ready yet. So I think personally for me, imposter syndrome goes away naturally with time.

What’s helpful for me is to forget about it and set a game plan for myself, and then make incremental progress day by day. And as you keep learning, at some point you will find that you are much more comfortable around these people than you ever thought you could be. And you’ll feel like the imposter syndrome magically disappeared, but really you conquered it by learning new things and giving it time.

I also think that it really helps to stop comparing yourself to others. You really need to be honest with yourself and encourage yourself whenever you make progress, even if it’s small because at some point you’ll find out you’ve already made more progress than you would have expected.

What do you think that we can do as members of the quantum computing and physics community to inspire and encourage the next generation of women going into science?

You’ll probably make this decision when choosing your major in college. So it’s important to encourage students early on, like during high school, and to get women interested in physics before they enter college. Having more educational programs or on-site programs that high school students can experience and participate in would really drive more excitement.

For example, being able to spend a few days as a researcher in a university or corporate lab and watch what goes on. I think getting students excited when they are still in high school would really pay off when they are older. Because normally by the time you’re in college, you already have an idea of what major you want to pursue. So by giving younger students more opportunities to see what working in quantum computing and physics is really like, it can open more doors for them later on.

If you could give some advice to your high school self, what would it be?

I would tell myself to enjoy every step, no matter if it’s big or small. Enjoy it, try your best and follow your passion.

Regardless of if you’re successful or not right away, as long as you work hard, all of your efforts will pay off eventually. And science teaches you that you actually learn a lot from failure. So every step counts.

Are there any tips that you would give to women who are interested in studying physics?

First and foremost, you should follow your passion and your intuition when you choose what you want to do. And really trust yourself, and then go for it, without comparing yourself to others.

Also, I think it is worthwhile to read some biographies and books on the history of science. Then you’ll have a bigger picture of how science and research changed and developed over time, and this will help you in deciding what path you want to take in your science career.

Never stop asking questions. And then after asking questions, work hard and look for the answers.