Effective bias and potentials in steady-state quantum transport : A NEGF reverse-engineering study
Karlsson, D., & Verdozzi, C. (2016). Effective bias and potentials in steady-state quantum transport : A NEGF reverse-engineering study. In Progress in Non-equilibrium Green’s Functions (PNGF VI) (pp. 012018). Journal of Physics: Conference Series, 696. Institute of Physics Publishing Ltd.. doi:10.1088/1742-6596/696/1/012018
Published inJournal of Physics: Conference Series;696
© Published under licence by IOP Publishing Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) licence.
Using non-equilibrium Green’s functions combined with many-body perturbation theory, we have calculated steady-state densities and currents through short interacting chains subject to a finite electric bias. By using a steady-state reverse-engineering procedure, the effective potential and bias which reproduce such densities and currents in a non-interacting system have been determined. The role of the effective bias is characterised with the aid of the so-called exchange-correlation bias, recently introduced in a steady-state density-functionaltheory formulation for partitioned systems. We find that the effective bias (or, equivalently, the exchange-correlation bias) depends strongly on the interaction strength and the length of the central (chain) region. Moreover, it is rather sensitive to the level of many-body approximation used. Our study shows the importance of the effective/exchange-correlation bias out of equilibrium, thereby offering hints on how to improve the description of densityfunctional-theory based approaches to quantum transport. ...