Charge Transport in Weyl Semimetals

Abstract

We study transport in three dimensional Weyl semimetals with N isotropic Weyl nodes in the presence of Coulomb interactions or disorder at temperature T. In the interacting clean limit, we determine the conductivity by solving a quantum Boltzmann equation within a `leading log' approximation and find it to be proportional to T, upto logarithmic factors arising from the flow of couplings. In the noninteracting disordered case, we compute the finite-frequency Kubo conductivity and show that it exhibits distinct behaviors for omega << T and omega >> T: in the former regime we recover the results of a previous analysis, of a finite conductivity and a Drude width that vanishes as NT^2; in the latter, we find a conductivity that vanishes linearly with omega whose leading contribution as T -> 0 is the same as that of the clean, non-interacting system sigma(omega, T=0) = N(e^2/12h)(|omega|/v_F). We compare our results to experimental data on Y2Ir2O7 and also comment on the possible relevance to recent transport data on Eu2Ir2O7.