Simulation of quantum transport in quantum devices with spatially varying effective mass

The authors report progress in quantum-mechanical simulation based on the Wigner function model. An exact nonlocal formulation in the Wigner representation due to a spatially varying effective mass and its discretization for numerical calculation are discussed. To verify the validity of such a formulation, the current-voltage characteristics of resonant tunneling diodes are simulated to compare with the conventional Wigner function model. The authors also point out the importance of self-consistent calculation in the electrostatic potential for precise device simulation. The emphasize that the Wigner function model is superior to the alternative method based on the transmission probability method even for the static simulation of quantum transport