Kevin Zhou

I’m a postdoctoral researcher at the UC Berkeley Leinweber Institute for Theoretical Physics.

Precision measurement technology is advancing rapidly, and my work focuses on using it to accelerate the discovery of physics beyond the Standard Model. To do this, I find novel laboratory signals of new fundamental particles, consistent with relativity and quantum mechanics, and work with experimentalists to develop effective “tabletop” detectors.

For instance, I have worked on searches for axion dark matter using superconducting cavities, now pursued in America, Europe, and China. I have also investigated infrared modifications of electromagnetism and gravity from continuous spin, new signals of axial vector dark matter, and the quantum effects of gravitational waves.

Previously, I got my PhD at Stanford in 2024, Master’s degrees at Cambridge and Oxford, and a Bachelor’s degree at MIT. During that time I spent a lot of energy on physics education, and I’m still always interested in hearing a good physics puzzle.

I can be reached at kzhou7@berkeley.edu, and a complete CV is available here.

Recent Papers

Each paper comes with talk slides, which provide an illustrated introduction.

Y. Bao, D. Y. Cheong, N. Rodd, J. Takach, L.-T. Wang, K. Zhou

July 2026

Suppressed Quantum Effects of Weakly Coupled Waves

Intrinsically quantum effects of gravitational waves and dark matter carry extra powers of the weak coupling, relative to classical effects. This strong suppression can only be evaded using highly nonclassical detector states.

arXiv Talk slides

F. Day, R. Harnik, Y. Kahn, S. Pavaskar, K. Zhou

November 2025 JHEP

Quantum Calculations of the Cavity Shift in Electron Magnetic Moment Measurements

Conducting walls have a very small, but observable effect on measurements of electron $g-2$. We compute it from first principles with quantum field theory, and show how it can be accounted for in future measurements.

arXiv JHEP Talk slides Talk video

Y. Bao, D. Y. Cheong, N. Rodd, J. Takach, L.-T. Wang, K. Zhou

October 2025 Phys. Rev. Lett.

Intrinsically Quantum Effects of Axion Dark Matter are Undetectable

Intrinsically quantum effects of axion dark matter are always highly suppressed, and in practice undetectable. Thus, even though the axion may be in a nonclassical state, it can still be treated as a classical field.

arXiv Phys. Rev. Lett. Talk slides

Z. Li, K. Zhou, M. Oriunno, A. Berlin, S. Calatroni, R. Tito D’Agnolo, S. Ellis, P. Schuster, S. Tantawi, N. Toro

July 2025 NIMA

A Prototype Hybrid Mode Cavity for Heterodyne Axion Detection

The heterodyne approach to axion detection enhances the axion signal power. A prototype cavity was designed and tested, with a novel geometry that maximizes signal, suppresses noise, and allows a wide tuning range.

arXiv NIMA Talk slides

A. Berlin, A. Millar, T. Trickle, K. Zhou

April 2025 Phys. Rev. D

Determining Spin-Dependent Light Dark Matter Rates from Neutron Scattering

Light dark matter particles could couple directly to electron spin. Since the same is true for neutrons, existing neutron scattering data can accurately predict the signal rate of a dark matter experiment.

arXiv Phys. Rev. D Talk slides

See all publications

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 made new problem sets, which strike a balance between traditional particle physics and connections to other fields. I gave weekly sections which laid out the big picture and trained problem solving skills.

Problem sets: 1, 2, 3, 4, 5, 6, 7, 8, 9 | Solutions: 1, 2, 3, 4, 5, 6, 7, 8, 9
Very rough section notes: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
Final exam | Solutions

Physics Olympiad Handouts

From 2019 to 2024, I coached the US Physics Team and wrote many of its exam questions and solutions, while developing a comprehensive set of training material. These handouts are the result. They contain 1,000 tricky, solved problems covering a very wide range of ideas, along with hundreds of examples and remarks. For details, see the syllabus and FAQ. To see if you’re ready to start the handouts, try the preliminary problems (answers here).

Core Curriculum

Problem Solving I (Sol), Problem Solving II (Sol)
Mech I (Sol), Mech II (Sol), Mech III (Sol), Mech IV (Sol)
Elec I (Sol), Elec II (Sol), Elec III (Sol), Elec IV (Sol)
Mech V (Sol), Mech VI (Sol), Mech VII (Sol)
Thermo I (Sol), Thermo II (Sol), Thermo III (Sol)
Elec V (Sol), Elec VI (Sol), Elec VII (Sol)
Relativity I (Sol), Relativity II (Sol)
Waves I (Sol), Waves II (Sol), Modern I (Sol)

Supplemental Topics, Review, and Practice Olympiads

Mech VIII (Sol), Elec VIII (Sol), Relativity III (Sol)
Waves III (Sol), Modern II (Sol), Modern III (Sol)
Mech Review (Sol), Elec Review (Sol), Other Review (Sol)
USAPhO-M (Sol), USAPhO-E (Sol), USAPhO-X (Sol)
USAPhO-A (Sol), USAPhO-B (Sol), USAPhO-C (Sol), USAPhO-D (Sol)
Expt (Sol), Final (Sol)

I don’t currently write or run the USAPhO, and I don’t have time to tutor, but I do still update the handouts occasionally; feel free to reach out (at my personal address, kzhou7@gmail.com) if you find an issue or have a suggestion. For Russian translations, see Physics Hub.

Notes

These are my notes from learning physics at MIT, Cambridge’s Part III and Oxford’s MMathPhys. I use them for personal reference, but they’re terse, and not good to learn from. If you like the style, you can download a TeX template here.

Writing

Advice

Learning Introductory Physics. A FAQ for high school students who want to start learning physics or taking part in physics competitions, such as the USAPhO.
After Introductory Physics. Some tips for self-taught students on what to do after mastering the basics, including book recommendations and online resources.
Physics Activities. Some places you can apply your physics knowledge in high school.
The Theoretical Minimum. A short list of canonical books you could self-study, to go from the level of introductory physics to PhD candidacy.
The Stanford Physics Qualifying Exam. A transcript of my PhD qualifying exam, and advice.

Expository

The Surprising Subtlety of Electrostatic Field Lines. A fun puzzle in electrostatics and its resolution with differential geometry; coauthored with Tomas Brauner.
Novel Searches for Physics Beyond the Standard Model. My Stanford PhD dissertation, covering several new types of experimental searches, and their motivation.
Cosmological Relaxation. My Oxford MSc dissertation, reviewing models that “relax” the Higgs boson’s mass, and motivations for model building.
The Meaning of Nothing. The New College Demuth prize essay, on how theoretical stories map onto reality, and why a physicist’s philosophical flexibility is a useful tool. Published in the New College Record with a wonderful illustration by Audrey Effenberger.

Links

Here are some memorable articles about science and everything else.
Here are some fun videos for a rainy day.
My 1,000 answers on Physics StackExchange have 3 million views; here’s a sample.