Prediction of a Weyl semimetal in Hg_(1-x-y)Cd_xMn_yTe

摘要

We study strained Hg_(1-x-y)Cd_xMn_y Te in a magnetic field using a k · p model and predict that the system is a Weyl semimetal with two nodes in an experimentally reasonable region of the phase diagram. We also predict two signatures of the Weyl semimetal phase which arise from tunability of the Weyl node splitting/First, we find that the Hall conductivity is proportional to the average Mn ion spin and thus is strongly temperature dependent. Second, we find an unusual magnetic field angle dependence of the Hall conductivity; in particular, we predict a peak in σ_(xy) as a function of field angle in the xz plane and a finite σ_(yx) as the x component of the field goes to zero.