Density of states and magnetotransport in Weyl semimetals with long-range disorder

Abstract

We study the density of states and magnetotransport properties of disordered Weyl semimetals, focusing on the case of a strong long-range disorder. To calculate the disorder-averaged density of states close to nodal points, we treat exactly the long-range random potential fluctuations produced by charged impurities, while the short-range component of disorder potential is included systematically and controllably with the help of a diagram technique. We find that for energies close to the degeneracy point, long-range potential fluctuations lead to a finite density of states. In the context of transport, we discuss that a self-consistent theory of screening in magnetic field may conceivably lead to non-monotonic low-field magnetoresistance.

Magnetoconductivity in Weyl semimetals: Effect of chemical potential and temperature

“…Contrary to previous work [28,30], in which the authors focused on a discussion of the case with μ = 0 and the role played by the zeroth Landau level, we focus on the situation in which the chemical potential is away from the μ = 0 neutrality point in order to answer the question of whether linear magnetoresistance can occur in this regime within the self-energy approximations. We notice that in experiments, the chemical potential in Weyl semimetal samples is usually away from 0, and thus not only the zeroth Landau level but also the higher Landau levels with index n 1 should play important roles.…”

“…First we give explanations for the Hamiltonian of the system. In the literature, for this model two different representations are usually used: one of them was adopted by Abrikosov [27], and the other was adopted recently by Klier et al and others [28,30]. We explicitly demonstrate that the two different representations are identical, and thus the choice of the representation is based only on convenience.…”

“…The key point in the calculation of the self-energy is to correctly evaluate the overlapping integrals between Landau levels. This is only done approximately in the existing literature [27,28,30]. The approximations in those studies are only valid when few Landau levels are involved.…”

“…Abrikosov showed that in a Dirac electronic spectrum, when the chemical potential coincides with the zeroth Landau level, linear magnetoresistance is obtained in the Born approximation in a model with long-range changed impurities scattering. Recent papers [28,30] have reexamined this problem in detail with the self-consistent Born approximation. In particular, Ref.…”

“…Motivated by these experimental observations and the theoretical progress [31], in this work we calculate the magnetoconductivities in a Weyl semimetal in the presence of charged impurities, which are crucial for the appearance of linear magnetoresistance within the self-energy approximation adopted here [27,28,30]. Contrary to previous work [28,30], in which the authors focused on a discussion of the case with μ = 0 and the role played by the zeroth Landau level, we focus on the situation in which the chemical potential is away from the μ = 0 neutrality point in order to answer the question of whether linear magnetoresistance can occur in this regime within the self-energy approximations.…”