Strongly coupled ultracompressed self-cavity plasmon polaritons at millikelvin temperatures

@misc{zhang2026strongly,
  title = {{Strongly coupled ultracompressed self-cavity plasmon polaritons at millikelvin temperatures}},
  author = {Luojia Zhang and Andrew T. Pierce and Xuepeng Wang and Simon Reinhardt and Kenji Watanabe and Takashi Taniguchi and Kin Fai Mak and Jie Shan and Debanjan Chowdhury and Valla Fatemi},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.00473},
  eprint = {2610.00473},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.00473},
}

TY  - UNPB
TI  - Strongly coupled ultracompressed self-cavity plasmon polaritons at millikelvin temperatures
AU  - Luojia Zhang
AU  - Andrew T. Pierce
AU  - Xuepeng Wang
AU  - Simon Reinhardt
AU  - Kenji Watanabe
AU  - Takashi Taniguchi
AU  - Kin Fai Mak
AU  - Jie Shan
AU  - Debanjan Chowdhury
AU  - Valla Fatemi
PY  - 2026
DA  - 2026/10/01
PB  - arXiv
DO  - 10.48550/arxiv.2610.00473
UR  - https://arxiv.org/abs/2610.00473
AB  - Van der Waals heterostructures exhibit self-cavity resonances from sub-terahertz to terahertz frequencies and thus offer an attractive route toward realizing cavity-modified phases of matter. Spectroscopy of such systems calls for high frequency resolution at millikelvin temperatures, which is extremely challenging with existing methods. Here we demonstrate a new platform for realizing and probing such systems. Superconducting layers define self-cavity structures with electromagnetic volume compression of order 10^7. With an integrated graphene layer, we observe underdamped cavity plasmon polaritons at frequencies as low as 0.04 THz and which exhibit avoided crossings with cavity modes. To measure such spectra, we deploy a millikelvin-compatible sub-THz spectrometer based on a superconducting circuit. This work paves the way for simultaneous spectroscopy and transport measurements of cavity-matter hybrid systems at millikelvin temperatures.
ER  -