Temperature effects in tilted Weyl semimetals: Dichroism and dynamic Hall angle

Abstract

In a tilted doped Weyl semimetal there are well-defined ranges of photon energies where there is dichroism. These correspond to regions of energy where the imaginary part of the dynamic Hall conductivity is finite. Such regions can involve contributions from both negative and positive chirality nodes or just one of them. As the temperature $(T)$ is increased, the boundaries of the regions of finite dichroism become smeared out in energy and extend beyond their original range for $T=0$ and at the same time the dichroism is reduced. When $T$ is increased to be of the order of the chemical potential associated with the doping, the dichroism vanishes completely. We have also extended the work to include the dynamic Hall angle which is found to behave in an analogous way. We treat the case when both chirality nodes have the same value of chemical potential, as well as when the two nodes are displaced in energy by an amount $\ifmmode\pm\else\textpm\fi{}{\mathcal{Q}}_{0}$ due to broken inversion symmetry. Further, we have included the impurity effect within the framework of the first-order Born approximation to analyze the absorptive parts of longitudinal and Hall conductivity at a finite temperature.