Chiral Wave-packet Scattering in Weyl Semimetals

TL;DR

This paper investigates wave-packet scattering in Weyl semimetals, revealing a chirality-protected shift that influences scattering probabilities and explains the ultrahigh mobility observed experimentally.

Contribution

It introduces the concept of chirality-protected shifts in wave-packet scattering and links this to anomalous transport properties in Weyl semimetals.

Findings

Chirality-protected shift occurs during impurity scattering.

The ratio of transport to quantum lifetime increases near Weyl nodes.

Explains ultrahigh mobility in topological semimetals.

Abstract

In quantum mechanics, a particle is best described by the wave packet instead of the plane wave. Here, we study the wave-packet scattering problem in Weyl semimetals with the low-energy Weyl fermions of different chiralities. Our results show that the wave packet acquires a chirality-protected shift in the single impurity scattering process. More importantly, the chirality-protected shift can lead to an anomalous scattering probability, thus, affects the transport properties in Weyl semimetals. We find that the ratio between the transport lifetime and the quantum lifetime increases sharply when the Fermi energy approaches to the Weyl nodes, providing an explanation on the experimentally observed the ultrahigh mobility in topological (Weyl or Dirac) semimetals.