Atomistic quantum transport approach to time-resolved device simulations

Having access to time-resolved quantum transport data is beneficial for more accurate calculation of energy/delay device characteristics during turn on, for studying novel effects based on the wave function phase manipulation, and as an alternative research path to simulating dissipation and nonlocal scattering in real time. We present a time-resolved version of the quantum transmitting boundary method that relies on the efficient algorithms developed previously for the steady state version. Our method in principle can handle arbitrary time-dependent bias at gate and current-carrying lead terminals, where leads are limited to rigid spatial potential, and arbitrary atomistic geometries in the semi-empirical tight-binding basis. Using our method in the wide-band approximation, therefore relaxing the numerical complexities of energy scattering, we present the time-resolved results for important device quantities and discuss the limitations of the wide band approximation. We also discuss the potential of this method for parallelization by showing the computation time versus number of processes scaling results for multiple levels of parallelization.