Weak antilocalization in Cd3As2 thin films

TL;DR

This study investigates weak antilocalization effects in 50nm-thick Cd3As2 thin films, revealing quantum interference phenomena consistent with 2D Dirac fermions and electron-electron interactions affecting dephasing.

Contribution

First experimental observation of weak antilocalization in Cd3As2 thin films using magnetoresistance measurements and HLN theory analysis.

Findings

Weak antilocalization observed under perpendicular magnetic field.

Electron-electron interactions contribute to dephasing.

Antilocalization also seen with magnetic field parallel to electric field.

Abstract

Recently, it has been theoretically predicted that Cd3As2 is a three dimensional Dirac material, a new topological phase discovered after topological insulators, which exhibits a linear energy dispersion in the bulk with massless Dirac fermions. Here, we report on the low-temperature magnetoresistance measurements on a ~50nm-thick Cd3As2 film. The weak antilocalization under perpendicular magnetic field is discussed based on the two-dimensional Hikami-Larkin-Nagaoka (HLN) theory. The electron-electron interaction is addressed as the source of the dephasing based on the temperature-dependent scaling behavior. The weak antilocalization can be also observed while the magnetic field is parallel to the electric field due to the strong interaction between the different conductance channels in this quasi-two-dimensional film.