CPM Seminar

Van Roosbroeck's equations with topological terms: The case of Weyl semimetals

Ion Garate

Département de physique
Université de Sherbrooke

Van Roosbroeck's equations constitute a versatile tool to determine the dynamics of electrons under time- and space-dependent perturbations. Extensively utilized in ordinary semiconductors, their potential to model devices made from topological materials remains untapped. In this talk, I will discuss recent work where we have adapted van Roosbroeck's equations to study the bulk response of a Weyl semimetal to an ultrafast and spatially localized light pulse in the presence of a quantizing magnetic field. We predict a transient oscillatory photovoltage that originates from the chiral anomaly. The oscillations take place at the plasma frequency (THz range) and are damped by intervalley scattering and dielectric relaxation. Our results illustrate the ability of van Roosbroeck's equations to unveil the interplay between electronic band topology and fast carrier dynamics in microelectronic devices.

Reference.: P.-A. Graham, S. Bertrand, M. Bédard, R. Durand and I. Garate, PRB 108, 024301 (2023).