The quantum Rabi model exhibits a superradiant phase transition when the coupling becomes strong, even though it involves only two components: a two-level atom and a single bosonic mode. This phase transition is referred to as a finite-component quantum phase transition, in contrast to conventional phase transitions in many-body systems. In this Letter, we investigate heat transport across an atom embedded in bosonic modes, modeled by the quantum Rabi model, between two thermal baths. We found a manifestation of the superradiant phase transition in the thermal conductance, which represents the linear response to a temperature bias. Our Letter can be helpful for the development of quantum heat devices utilizing controllable finite-component quantum phase transitions.
@article{arxiv.2502.14447,
title = {Thermal conductance at the superradiant phase transition in the quantum Rabi model},
author = {Tsuyoshi Yamamoto and Yasuhiro Tokura},
journal= {arXiv preprint arXiv:2502.14447},
year = {2025}
}