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Kevin Zhou

Biography

I’m a postdoctoral researcher at UC Berkeley and LBNL, working at the Berkeley Center for Theoretical Physics. I am primarily interested in accelerating the discovery of physics beyond the Standard Model through new kinds of precision experiments. Many of these ideas focus on detecting ultralight dark matter, though I’ve also thought about more radical possibilities, such as modifications of long-range forces due to continuous spin. A complete CV is available here.

Previously, I earned my PhD degree at Stanford in 2024, and Master’s degrees at Cambridge and Oxford. During that period I spent a lot of energy on physics education and outreach, and I’m still always interested in hearing a good physics puzzle. For research-related inquiries, you can reach me at kzhou7@berkeley.edu, and for everything else, try kzhou7@gmail.com.

Recent Papers

Physical Signatures of Fermion-Coupled Axion Dark Matter

The axion-fermion coupling induces spin-dependent forces and torques, which can lead to macroscopic currents. “Magnetized multilayer” setups can use these currents to probe orders of magnitude beyond existing bounds.

Interactions of Particles with "Continuous Spin" Fields

Observed long-range forces are traditionally assumed to be mediated by fields with exactly zero spin scale. We present the first theory of matter particles interacting with “continuous spin” fields with arbitrary $\rho$, and show that there are calculable, universal, observable $\rho$-dependent modifications from familiar gauge theories.

Discovering QCD-Coupled Axion Dark Matter with Polarization Haloscopes

QCD axion dark matter induces oscillating EDMs, yielding physical currents that can be amplified in a microwave cavity. This setup has the unique ability to test whether a cavity haloscope signal arises from the QCD axion.

Probing Invisible Vector Meson Decays with NA64 and LDMX

Electron beam fixed target experiments such as NA64 and LDMX can improve constraints on invisible light vector meson decays by $5$ orders of magnitude, enhancing their sensitivity to dark matter of mass $m_\chi \gtrsim 0.1 \ \mathrm{GeV}$.

Teaching

Quantum Field Theory I (Physics 330)

In Autumn 2022, I was the TA for Stanford’s introductory quantum field theory class, taught by Prof. Bernhard Mistlberger. We overhauled the course and produced new problem sets, which we believe strike a good balance between traditional particle physics applications, and connections to other fields. I also taught weekly sections which laid out the big picture and showed tricks for doing the problems efficiently.

Physics Olympiad Handouts

From 2021 to 2024, I coached the US Physics Team and wrote a good chunk of its exam questions, while developing a comprehensive set of training material. These handouts are the result. They contain full explanations of all the problem solving techniques used in the USAPhO and IPhO, hundreds of illustrative examples, and about 1,000 tough questions, with solutions. For more details, see the syllabus and FAQ. Usually, students take a year to work through the handouts; to see if you’re ready, try the preliminary problems (answers here).

Core Curriculum

Supplemental Topics, Review, and Practice Olympiads

Personal Notes

These are the notes I’ve taken while learning physics. I use them for reference, but they’re quite terse, and not a good resource to learn from. They weigh in at 1,900 pages and 750,000 words.

Undergraduate

These notes cover what I learned at MIT, through courses, lecture notes, and books.

Graduate

These notes follow courses taught at Cambridge’s Part III and Oxford’s MMathPhys.

If you like the style, you can download a TeX template here.

Writing

Advice

Expository