Hydrodynamic theory of thermoelectric transport and negative magnetoresistance in Weyl semimetals Journal Article

Overview

Significance; Weyl semimetals are exotic materials with negative electrical magnetoresistance: when an electric and magnetic field are applied in parallel, the induced electrical current increases upon increasing magnetic field strength. This is due to an emergent axial quantum anomaly in Weyl semimetals. We present a universal description of thermoelectric transport in weakly disordered Weyl semimetals where electron–electron interactions are faster than electron–impurity scattering. We predict negative thermal magnetoresistance: upon applying a parallel temperature gradient and magnetic field, the induced heat current increases with increasing magnetic field strength. This is caused by a distinct emergent quantum anomaly—the axial–gravitational anomaly. Measuring this effect may be the most practical route to experimentally observing this anomaly in any branch of physics.