Quantum transport studies of grain boundaries in p-Hg1−xMnxTe

We show that charged traps at grain boundaries in p-Hg1−xMnxTe lead to the formation of an inversion layer. The layers are dominant channels of electrical conductivity at low temperatures. By means of the Shubnikov–de Haas effect measurements we demonstrate that the electron gas in the layer forms a quasi-two-dimensional system. We determine electric subband populations and effective masses. We establish parameters of the potential well at the grain boundary within a simple model.