Magnetic impurity in a Weyl semimetal

Article

关键词: TOPOLOGICAL DIRAC SEMIMETAL;    FERMI ARCS;    RENORMALIZATION-GROUP;    ANDERSON MODEL;    KONDO PROBLEM;    INSULATORS;    DISCOVERY;    GRAPHENE;    ALLOYS;    TAAS;   

DOI  :  10.1103/PhysRevB.92.195124

来源: SCIE

【 摘 要 】

We utilize the variational method to study the Kondo screening of a spin-1/2 magnetic impurity in a three-dimensional (3D) Weyl semimetal with two Weyl nodes along the k(z) axis. The model reduces to a 3D Dirac semimetal when the separation of the two Weyl nodes vanishes. When the chemical potential lies at the nodal point, mu = 0, the impurity spin is screened only if the coupling between the impurity and the conduction electron exceeds a critical value. For finite but small mu, the impurity spin is weakly bound due to the low density of states, which is proportional to mu(2), contrary to that in a 2D Dirac metal such as graphene and 2D helical metal, where the density of states is proportional to vertical bar mu vertical bar. The spin-spin correlation function J(uv) (r) between the spin v component of the magnetic impurity at the origin and the spin u component of a conduction electron at spatial point r is found to be strongly anisotropic due to the spin-orbit coupling, and it decays in the power law. The main difference of the Kondo screening in 3D Weyl semimetals and in Dirac semimetals is in the spin x (y) component of the correlation function in the spatial direction of the z axis.

【 授权许可】

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