Calculation of the current response in a nanojunction for an arbitrary time-dependent bias: application to the molecular wire

Abstract

PAPER • OPEN ACCESS Calculation of the current response in a nanojunction for an arbitrary time-dependent bias: application to the molecular wire Michael Ridley1,2, Angus MacKinnon2 and Lev Kantorovich1 Published under licence by IOP Publishing Ltd Journal of Physics: Conference Series, Volume 696, Number 1 Article PDF 12 Total downloads Export citation and abstract BibTeX RIS Share this article Article information Abstract Recently [Phys. Rev. B 91, 125433 (2015)] we derived a general formula for the time-dependent quantum electron current through a molecular junction subject to an arbitrary time-dependent bias within the Wide Band Limit Approximation (WBLA) and assuming a single particle Hamiltonian. Here we present an efficient numerical scheme for calculating the current and particle number. Using the Padé expansion of the Fermi function, it is shown that all frequency integrals occurring in the general formula for the current can be removed analytically. When the bias in the reservoirs is assumed to be sinusoidal it is possible to manipulate the general formula into a form containing only summations over special functions. To illustrate the method, we consider electron transport through a one-dimensional molecular wire coupled to two leads subject to out-of-phase biases. We also investigate finite size effects in the current response and particle number that result from the switch-on of this bias.