Thermal Hall response: violation of gravitational analogues and Einstein relations
Abstract
The response of solids to temperature gradients is often described in terms of a gravitational analogue: the effect of a space-dependent temperature is modeled using a space dependent metric. We investigate the validity of this approach in describing the bulk response of quantum Hall states and other gapped chiral topological states. To this end, we consider the prototypical Haldane model in two different cases of (i) a space-dependent electrostatic potential and gravitational potential and (ii) a space-dependent temperature and chemical potential imprinted by a weak coupling to non-interacting electron baths and phonons. We find that the thermal analogue is \textit{invalid}; while a space dependent gravitational potential induces transverse energy currents proportional to the third derivative of the gravitational potential, the response to an analogous temperature profile vanishes in limit of weak coupling to the thermal bath. Similarly, the Einstein relation, the analogy between the electrostatic potential and the internal chemical potential, is not valid in such a setup.
Keywords
Cite
@article{arxiv.2108.06162,
title = {Thermal Hall response: violation of gravitational analogues and Einstein relations},
author = {Jinhong Park and Omri Golan and Yuval Vinkler-Aviv and Achim Rosch},
journal= {arXiv preprint arXiv:2108.06162},
year = {2022}
}
Comments
In the latest version, we have added the part to include phonon baths for internal equilibration and a more realistic way to imprint a temperature profile onto the system. 17 pages (5 pages for the main text and 12 pages for the supplementary material), 8 figures (4+4)