Electric-field-induced lifting of the valley degeneracy in α-(BEDT-TTF)2I3 Dirac-like Landau levels

The relativistic Landau levels in the layered organic material alpha-(BEDT-TTF)(2)I-3 (BEDT-TTF=bis(ethylenedithio)tetrathiafulvalene) are sensitive to the tilt of the Dirac cones, which, as in the case of graphene, determine the low-energy electronic properties under appropriate pressure. We show that an applied in-plane electric field, which happens to be in competition with the tilt of the cones, lifts the twofold valley degeneracy due to a different level spacing. This scenario may be tested in infrared transmission spectroscopy. Copyright (C) EPLA, 2009