Cyclotron resonance of figure-of-eight orbits in a type-II Weyl semimetal

TL;DR

This paper investigates the unique cyclotron resonance behavior in a type-II Weyl semimetal, revealing anisotropic resonant frequencies linked to figure-of-eight electron orbits on a dumbbell-shaped Fermi surface.

Contribution

It introduces a theoretical analysis of cyclotron resonance in type-II Weyl semimetals, highlighting the anisotropic resonance frequencies due to figure-of-eight orbits.

Findings

Resonant frequencies in x and y directions differ by a factor of two.

Anisotropic cyclotron resonance reflects the figure-of-eight electron motion.

Unique resonance characteristic of the dumbbell-like Fermi surface.

Abstract

We study the cyclotron resonance in the electron-hole joint Fermi surface of a type-II Weyl semimetal. In magnetic field, the electron and hole pockets touching at the Weyl node are hybridized to form quantized Landau levels corresponding to semiclassical 8-shaped orbits. We calculate the dynamical conductivities for the electric fields oscillating in $x$ and $y$-directions and find that the resonant frequencies in $x$ and $y$ differ by the factor of two, reflecting to the figure-of-eight electron motion in the real space. The peculiar anisotropy in the cyclotron resonance serves as a unique characteristic of the dumbbell-like Fermi surface.