Three Dimensional Dirac Semimetal and Quantum Transports in Cd3As2

TL;DR

This paper uses first-principles calculations to reveal the topological semimetal nature of Cd3As2, highlighting its Dirac points, surface Fermi arcs, and potential for various topological phases and quantum transport phenomena.

Contribution

It uncovers the symmetry-protected topological properties of Cd3As2 and predicts its ability to transition into different topological states under symmetry breaking or dimensional reduction.

Findings

Cd3As2 is a symmetry-protected topological semimetal with 3D Dirac points.

Supports sizable linear quantum magnetoresistance at room temperature.

Can transition into topological insulator, Weyl semimetal, or quantum spin Hall insulator.

Abstract

Based on the first-principles calculations, we recover the silent topological nature of Cd3As2, a well known semiconductor with high carrier mobility. We find that it is a symmetry-protected topological semimetal with a single pair of three-dimensional (3D) Dirac points in the bulk and non-trivial Fermi arcs on the surfaces. It can be driven into a topological insulator and a Weyl semi-metal state by symmetry breaking, or into a quantum spin Hall insulator with gap more than 100meV by reducing dimensionality. We propose that the 3D Dirac cones in the bulk of Cd3As2 can support sizable linear quantum magnetoresistance even up to room temperature.