On the Topological Protection of the Quantum Hall Effect in a Cavity

• DOI: 10.48550/arxiv.2305.10558
• Publication Date: 2023-01-01
• Authors: Vasil Rokaj; Jie Wang; John Sous; Markus Penz; Michael Ruggenthaler; Ángel Rubio
• Keywords: Landau quantization

We study the quantum Hall effect in a two-dimensional homogeneous electron gas coupled to cavity field. As initially pointed out by Kohn, Galilean invariance for system implies that electronic center of mass (c.m.) decouples from electron-electron interaction, and energy c.m. mode, also known as Kohn is equal single particle cyclotron transition. In this work, we point strong light-matter hybridization between mode photons gives rise collective hybrid modes Landau levels photons. provide exact solution polaritons demonstrate weakening topological protection at zero temperature due existence lower polariton which softer than mode. This provides an intrinsic mechanism recently observed breakdown [F. Appugliese et al., Breakdown vacuum fields integer effect, Science 375, 1030 (2022).SCIEAS0036-807510.1126/science.abl5818]. Importantly, our theory predicts suppression thermal activation gap transport. Our work paves way future developments control materials.