University of Illinois Urbana-Champaign · Department of Physics

About Condensed-matter theorist working on magnonics, topology, and quantum information.

I am a theoretical condensed-matter physicist interested in the boundary between quantum information and many-body physics. My work focuses on magnonic systems and cavity-magnon coupling, topological phases in nodal-line semimetals, and the computational complexity of bosonic quantum devices. I completed my B.S. in physics and mathematics at the University of Texas at Austin in December 2025, and will begin my Ph.D. in physics at the University of Illinois Urbana-Champaign in the fall of 2026.

I use quantum-information tools to tackle condensed-matter problems, and many-body techniques to design better qubits. The projects I find most rewarding live at that collision — where it is not obvious in advance which tradition should do the work.

Latest preprint Q. Wang, A. Karthigeyan, C.-T. Chou, L. Liu. A room-temperature cavity-magnonic source of correlated microwave pairs. arXiv:2602.00287 (2026). If you work on magnonics, open quantum systems, or microwave quantum optics, I'd love to compare notes.

Selected publications

[1]
Q. Wang, A. Karthigeyan, C.-T. Chou, L. Liu
arXiv:2602.00287 · 2026
arXiv pdf bibtex
[2]
Continuous-time quantum search and boson sampling
A. Karthigeyan
Quantum Complexity course project, S. Aaronson, UT Austin · 2024
pdfbibtex

News

Research snapshot

Three ongoing threads — full writeups with the five-field rubric on the research page.

Magnonics

Spin-wave propagation, cavity-magnon coupling, and room-temperature parametric down-conversion of magnons.

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Topology

Stiefel–Whitney invariants in nodal-line semimetals and their transport signatures via the Kubo formula.

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Complexity

Continuous-time quantum search and boson-sampling-style hardness arguments for near-term photonic devices.

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Writing

Research updates, talk notes, and ideas worth writing down. RSS ↓

Contact

The fastest way to reach me is email: aravindkarthigeyan@utexas.edu.