Follow your passion.


I was inspired to study physics after encountering a few of Brian Greene’s books at a local library after my freshman year of college. I was fascinated by all the unsolved mysteries of the universe, and I thought that it would be a privilege to contribute some answers. However, not everyone around me was supportive. Some friends thought that physics was too difficult for girls, and suggested accounting or nursing.

My social circle at the time, in small-town Texas, had not encountered anyone who majored in physics, or knew about its career trajectories post-graduation. Faced with this pressure, I decided to major in electrical engineering as a compromise: engineering is also about exploring and implementing natural and physical laws, and a career as an engineer was something that my friends understood and supported.

But I couldn’t forget about physics, so I took courses on the side. I joined the Society of Physics Students, met others who were passionate about physics, and finally made the switch to become a physics major: I had found something I was passionate about and had found a new support group who understood and could guide me on my journey.

To any young woman who is excited about STEM but has people telling her that she can’t do it for one reason or another, I hope my story can inspire you to feel encouraged and empowered to pursue it.

Now, as a PhD candidate at Columbia University, my primary responsibilities are to conduct original research in the lab, and to communicate my findings with collaborators and the broader scientific community. My research is on optically characterizing lanthanide-based upconverting nanoparticles. More specifically, when I shine lasers on these tiny particles, they convert the invisible light (infrared) into visible ones. In 2021, I was part of the collaboration efforts that discovered the photon-avalanching phenomenon in a certain configuration of these particles. This finding was published and featured on the cover of Nature magazine. It has many exciting potential applications including night vision, bioimaging, and sensing.

I find it exciting to go into the lab every day, knowing what I’m doing is novel, and that it could positively impact society in the future.


Emma Xu
PhD Candidate, Mechanical Engineering, Columbia University
Born in China / Resides in United States
Educational Background: BS, University of Texas at Dallas; MS and MPhil, Columbia University, United States

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