Affiliation:
1. Department of Physics, University of North Bengal, Rajarammounpur, Darjeeling- 734013
Abstract
The existence of two inequivalent valleys in the Brillouin zone of some two-dimensional crystals with honeycomb lattice structure provides electrons to possess an extra degree of freedom, known as pseudospin/valley in addition to their intrinsic charge and spin. A dice lattice, in which
the low energy excitations are described by the Dirac-Weyl Hamiltonian with pseudospin S = 1, also has the valley degree of freedom. Here, we consider an inversion-symmetry broken low energy model of a symmetrically biased dice lattice. We find that the Berry curvature has equal magnitude
with opposite signs in two valleys. This causes the electrons to acquire opposite anomalous velocities in the respective valleys. The Hall conductivity is calculated using the semi-classical formulation of electron dynamics. The dependence of the valley contrasted Hall conductivity on the
chemical potential at various temperatures is shown.
Publisher
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