Large extrinsic phonon thermal Hall effect from resonant scattering

Abstract

From a symmetry perspective, a magnetic field makes a material chiral and thus leads to a nonzero thermal Hall effect. However, recent experiments on a variety of interesting insulators -- including a number of cuprates -- have uncovered an unexpectedly large field-induced thermal Hall effect, despite the fact that there are no low-energy charge-carrying excitations, i.e., itinerant electrons. The authors propose here a mechanism of coupling a magnetic field to phonons and producing a thermal Hall response of the requisite magnitude through resonant skew scattering of phonons from a certain class of three-level systems.

Topics & Concepts