Work

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

Year: 2026

Type: preprint

Abstract: 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 $ω\gtrsim5Δ$, establishing the Lindhard function as a robust approximation for superconducting DM detectors operating in this regime.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2609.06423

Authors: Gan, Chengyao, Li, Hui, Li, Wenjing, Liang, Zheng-Liang, Zhang, Lin, Zheng, Fawei

Institutions: Beijing University of Chemical Technology, Wuhan University of Technology, Beijing Institute of Technology, Sun Yat-sen University

Language: English

Topic: Dark Matter and Cosmic Phenomena

Subfield: Nuclear and High Energy Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: green

Funder: National Natural Science Foundation of China

Awards: G6204533721, G8325998809

OpenAlex ID: W7212053842

Cites:

Cited by:

Related to: 10