3D Dirac semimetal Cd3As2 : A review of material properties

Abstract

Cadmium arsenide (Cd3As2) -a time-honored and widely explored material in solid-state physics -has recently attracted considerable attention. This was triggered by a theoretical prediction concerning the presence of 3D symmetry-protected massless Dirac electrons, which could turn Cd3As2 into a 3D analogue of graphene. Subsequent extended experimental studies have provided us with compelling experimental evidence of conical bands in this system, and revealed a number of interesting properties and phenomena. At the same time, some of the material properties remain the subject of vast discussions despite recent intensive experimental and theoretical efforts, which may hinder the progress in understanding and applications of this appealing material. In this review, we focus on the basic material parameters and properties of Cd3As2, in particular those which are directly related to the conical features in the electronic band structure of this material. The outcome of experimental investigations, performed on Cd3As2 using various spectroscopic and transport techniques within the past sixty years, is compared with theoretical studies. These theoretical works gave us not only simplified effective models, but more recently, also the electronic band structure calculated numerically using ab initio methods.

Topological Insulator State and Collapse of the Quantum Hall Effect in a Three-Dimensional Dirac Semimetal Heterojunction

“…Moreover, in each fan, the g factor must then change with the mass, so that the fans are approximately evenly spaced-this change is necessary to reproduce the observed steps of just one. This scenario is clearly unrealistic for Cd 3 As 2 , for which g is measured to be approximately 20, and the effective mass is found to be 0.03m e [8,19,22,39].…”

“…In this paper, we investigate the quantum Hall effect of thin, (001)-oriented cadmium arsenide (Cd 3 As 2 ), a prototype 3D Dirac semimetal [8,[18][19][20][21][22]. This combination of material, crystal orientation, and sample geometry is significant, because the two Dirac nodes lie along the k z axis and project onto the same point in the (001) surface Brillouin zone [8,23].…”

Soft phonons and ultralow lattice thermal conductivity in the Dirac semimetal Cd3As2

“…Cadmium arsenide (Cd 3 As 2 ) is a well-studied electronic material due to its semimetalicity and ultrahigh charge carrier mobility [1,2]. The research interest in Cd 3 As 2 has been revived recently due to both theoretical prediction [3] and experimental observations [4][5][6][7] that Cd 3 As 2 hosts three-dimensional linear Dirac bands [8]. Namely, the electronic structure of Cd 3 As 2 is a threedimensional analog to that of graphene.…”

Determination of the crystal field splitting energy in Cd3As2 using magnetooptics

“…It is well established that Cd3As2 is a three-dimensional semimetal. [1][2][3][4][5][6][7][8][9][10][11][12] Experimental measurements on this material have unambiguously revealed the presence of electrons with ultra-low effective mass (< 0.03 0 ) [3,13] and record high mobility (~10 5 cm²/Vs) in single crystals. [1] A magnetic field was argued to yield Weyl fermions in Cd3As2.…”

“…[16][17][18][19][20][21][22][23] As Cd3As2 is generally n-doped due to native defects. [24] [7] Achieving charge neutrality in the bulk system has proven difficult. The details of the band dispersion in the vicinity of Dirac nodes thus remained poorly understood.…”