Detecting individual light quanta is essential for quantum information, space exploration, advanced machine vision, and fundamental science. Here, we introduce a novel single photon detection mechanism using highly photosensitive non-equilibrium electron phases in moir\'e materials. Using tunable bands in bilayer graphene/hexagonal-boron nitride superlattices, we engineer negative differential conductance and a sensitive bistable state capable of detecting single photons. Operating in this regime, we demonstrate single-photon counting at mid-infrared (11.3 microns) and visible wavelengths (675 nanometres) and temperatures up to 25 K. This detector offers new prospects for broadband, high-temperature quantum technologies with CMOS compatibility and seamless integration into photonic integrated circuits (PICs). Our analysis suggests the mechanism underlying our device operation originates from negative differential velocity, and represents an important milestone in the field of high-bias transport in two-dimensional moir\'e quantum materials.
@article{arxiv.2505.13637,
title = {Single-photon detection enabled by negative differential conductivity in moir\'e superlattices},
author = {Krystian Nowakowski and Hitesh Agarwal and Sergey Slizovskiy and Robin Smeyers and Xueqiao Wang and Zhiren Zheng and Julien Barrier and David Barcons Ruiz and Geng Li and Riccardo Bertini and Matteo Ceccanti and Iacopo Torre and Bert Jorissen and Antoine Reserbat-Plantey and Kenji Watanabe and Takashi Taniguchi and Lucian Covaci and Milorad V. Milošević and Vladimir Fal'ko and Pablo Jarillo-Herrero and Roshan Krishna Kumar and Frank H. L. Koppens},
journal= {arXiv preprint arXiv:2505.13637},
year = {2025}
}