| Description |
We study the effects of spatial dispersion in disordered noncentrosymmetric metals. Specifically, we consider the kinetic magnetoelectric effect, and natural optical activity of metals, as well as the so-called dynamic chiral magnetic effect as a particular case of natural optical activity. These effects stem from the magnetic moments of quasiparticles near the Fermi surface. In addition to the well-known intrinsic contribution, we identify new disorder-induced extrinsic contributions to these magnetic moments that come from the skew-scattering and side-jump processes, familiar from the theory of the anomalous Hall effect. We show that at low frequencies the spatial dispersion of the conductivity tensor comes mainly from either the skew-scattering or intrinsic contribution, and there is always a region of frequencies in which the intrinsic mechanism dominates. However, our results imply that in clean three-dimensional metals, the kinetic magnetoelectric effect is in general determined by impurity skew scattering, rather than intrinsic contributions. Further, we study the kinetic magnetoelectric effect in three-dimensional conductors, specializing to the case of p-doped trigonal tellurium. We include both the intrinsic and extrinsic contributions to the effect, which stem from the band structure of the crystal, and from disorder scattering, respectively. Specifically, we determine the dependence of the kinetic magnetoelectric response on the hole doping in tellurium, and show that the intrinsic effects dominate for low levels of doping while extrinsic effects, in particular the skew-scattering mechanism, dominate for high levels of doping. The results of this work imply that three-dimensional helical metals are promising candidates for spintronics applications and in particular, they can provide robust control over current-induced magnetic torques. |
