A Mean-Field Approach to the Dielectric Response of Bulk Superconductors for Light Dark Matter Direct Detection

@misc{gan2026meanfield,
  title = {{A Mean-Field Approach to the Dielectric Response of Bulk Superconductors for Light Dark Matter Direct Detection}},
  author = {Chengyao Gan and Hui Li and Wenjing Li and Zheng-Liang Liang and Lin Zhang and Fawei Zheng},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.06423},
  eprint = {2609.06423},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.06423},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - A Mean-Field Approach to the Dielectric Response of Bulk Superconductors for Light Dark Matter Direct Detection
AU  - Chengyao Gan
AU  - Hui Li
AU  - Wenjing Li
AU  - Zheng-Liang Liang
AU  - Lin Zhang
AU  - Fawei Zheng
PY  - 2026
DA  - 2026/09/06
PB  - arXiv
DO  - 10.48550/arxiv.2609.06423
UR  - https://arxiv.org/abs/2609.06423
AB  - The dielectric function is central to describing many-body screening effects in dark matter (DM) direct detection with condensed matter targets. Current superconducting detector analyses employ the free-electron Lindhard dielectric function to model in-medium effects, an approximation whose validity in the superconducting state remains untested. We derive the electronic dielectric function for bulk superconductors within the Bardeen-Cooper-Schrieffer (BCS) framework, incorporating the full Bogoliubov quasiparticle coherence factors in the random-phase approximation. A systematic comparison with the Lindhard function for aluminum and tungsten silicide (WSi) reveals good agreement for energy depositions ω≳5Δ, establishing the Lindhard function as a robust approximation for superconducting DM detectors operating in this regime.
ER  -