Exchange-correlation effects in resonant-tunneling heterostructures

Using two different methods based on the local-density approximation, we investigate effects of exchange and correlation on resonant tunneling in heterostructures. Our self-consistent calculation of current and charge density in double-barrier structures shows that correlation effects largely cancel exchange effects. As a consequence, we find that the intrinsic bistability in the I-V curve is not suppressed by the exchange-correlation correction to the Hartree approximation. However, some narrowing of the width (20% in our case) of the bistable region can be expected.