Seminar über Theoretische Festkörperphysik
Room 10.01, 10th Floor, Bldg. 30.23, KIT Campus South
PD Dr. Igor Gornyi
Weyl semimetals provide an outstanding platform to probe the properties of three-dimensional relativistic massless electrons in condensed-matter setup. One of the theoretical predictions for such excitations is the so-called Chiral Magnetic Effect, which lies in appearance of electrical current proportional to the external magnetic field, but the current is known to vanish in thermal equilibrium. A simple and yet experimentally accessible way to probe the effect is to drive the system out of equilibrium by making the magnetic field time-dependent. We attempt to resolve the controversy present in the literature regarding the value of the coefficient entering the expression for the current, and to clarify the contributions of the bulk and the surface states therein. Apart from confirming the recent finding of Baireuther et al. (2016) that the boundary states contribute significantly to the current, we point out that such a surface contribution may become the only source of the Chiral Magnetic Effect in the limit of large sample sizes and large magnetic fields.