Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme

Details Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme

2009-11-09

arxiv.org/abs/0911.1718v2

Phys. Rev. B 81, 115446 (2010)

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

20 pages, 9 figures, published version

Scientific paper

In this work we put forward an exact one-particle framework to study nano-scale Josephson junctions out of equilibrium and propose a propagation scheme to calculate the time-dependent current in response to an external applied bias. Using a discrete basis set and Peierls phases for the electromagnetic field we prove that the current and pairing densities in a superconducting system of interacting electrons can be reproduced in a non-interacting Kohn-Sham (KS) system under the influence of different Peierls phases {\em and} of a pairing field. An extended Keldysh formalism for the non-equilibrium Nambu-Green's function (NEGF) is then introduced to calculate the short- and long-time response of the KS system. The equivalence between the NEGF approach and a combination of the static and time-dependent Bogoliubov-deGennes (BdG) equations is shown. For systems consisting of a finite region coupled to ${\cal N}$ superconducting semi-infinite leads we numerically solve the static BdG equations with a generalized wave-guide approach and their time-dependent version with an embedded Crank-Nicholson scheme. To demonstrate the feasibility of the propagation scheme we study two paradigmatic models, the single-level quantum dot and a tight-binding chain, under dc, ac and pulse biases. We provide a time-dependent picture of single and multiple Andreev reflections, show that Andreev bound states can be exploited to generate a zero-bias ac current of tunable frequency, and find a long-living resonant effect induced by microwave irradiation of appropriate frequency.

Affiliated with

Also associated with

No associations

Rating

Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time-dependent quantum transport with superconducting leads: a discrete basis Kohn-Sham formulation and propagation scheme will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-660517