Eur. Phys. J. B (2018) 91: 101
https://doi.org/10.1140/epjb/e2018-90184-7

Regular Article

Exchange-correlation functionals of i-DFT for asymmetrically coupled leads^★

¹ Nano-Bio Spectroscopy Group and European Theoretical Spectroscopy Facility (ETSF), Dpto. de Física de Materiales, Universidad del País Vasco UPV/EHU, Avenida Tolosa 72, 20018 San Sebastián, Spain
² IKERBASQUE, Basque Foundation for Science, María Díaz de Haro 3, 48013 Bilbao, Spain
³ Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain

^a e-mail: david.jacob@ehu.eus

Received: 19 March 2017
Received in final form: 13 April 2018
Published online: 4 June 2018

Abstract

A recently proposed density functional approach for steady-state transport through nanoscale systems (called i-DFT) is used to investigate junctions which are asymmetrically coupled to the leads and biased with asymmetric voltage drops. In the latter case, the system can simply be transformed to a physically equivalent one with symmetric voltage drop by a total energy shift of the entire system. For the former case, known exchange correlation gate and bias functionals have to be generalized to take into account the asymmetric coupling to the leads. We show how differential conductance spectra of the constant interaction model evolve with increasing asymmetry of both voltage drops and coupling to the leads.