Special CPM Seminar

Heat transport in Weyl semimetals in the hydrodynamic regime

Dima Gutman

Bar-Ilan University

We study transport and heat transport in a Weyl semimetal with broken time-reversal symmetry in two cases: non-interacting electrons and strong electron interaction limit, where electrons form a classical viscous fluid. For the non-interacting electrons, we compute the Hall conductivity and express it analytically in terms of the scattering phases. For the viscous electronic fluid, we focus on the heat conductivity and compute it near the neutrality point. The longitudinal heat conductivity is governed by the momentum relaxation (elastic) time, while longitudinal electric conductivity is controlled by the inelastic scattering time. In the hydrodynamic regime this leads to a large longitudinal Lorenz ratio. As the chemical potential is tuned away from the neutrality point, the longitudinal Lorenz ratio decreases because of the Seebeck effect's suppression of the heat conductivity. The Seebeck effect (thermopower) and the open circuit heat conductivity are intertwined with the electric conductivity. The magnitude of Seebeck tensor is parametrically enhanced, compared to the non-interacting model, in a wide parameter range. While the longitudinal component of Seebeck response decreases with increasing electric anomalous Hall conductivity, the transverse component depends on in a non-monotonous way.