Wigner Monte Carlo simulation of phonon-induced electron decoherence in semiconductor nanodevices

This paper examines the phonon-induced electron decoherence in semiconductor nanostructures and nanodevices within the Wigner transport equation, solved using a particle Monte Carlo technique. The Wigner-Boltzmann formalism is first established as a relevant and original approach to modeling electron quantum decoherence in semiconductors. The simulation of the time evolution of a free wave-packet then allows analyzing the competition between decoherence and wave-packet expansion in a semiconductor. It is additionally argued that decoherence occurs faster than in the widely studied case of quantum Brownian motion. The simulation of a wave packet interacting with a tunnel barrier allows studying the electron localization induced by decoherence. The case of a wave packet interacting with a double barrier puts forward the mechanism of decoherence-induced transition from resonant to sequential transport through a bound state. Finally the simulation of resonant tunneling devices shows how these phenomena take place in nanodevices and highlights the transition from the quantum transport regime to the semiclassical transport regime induced by phonon scattering.