Eur. Phys. J. B 78, 75-81 (2010)
https://doi.org/10.1140/epjb/e2010-10452-x

Electron transport across a quantum wire in the presence of electron leakage to a substrate

¹ Institut für Physik, Universität Augsburg, Univeristätsstr. 1, 86135 Augsburg, Germany
² Instytut Fizyki, Uniwersytet Marii Curie-Skłodowskiej, 20-031 Lublin, Poland
³ Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid, Spain

Corresponding author: ^a tomasz.kwapinski@umcs.lublin.pl

Received: 9 June 2010
Revised: 3 September 2010
Published online: 20 October 2010

Abstract

We investigate electron transport through a mono-atomic wire which is tunnel coupled to two electrodes and also to the underlying substrate. The setup is modeled by a tight-binding Hamiltonian and can be realized with a scanning tunnel microscope (STM). The transmission of the wire is obtained from the corresponding Green's function. If the wire is scanned by the contacting STM tip, the conductance as a function of the tip position exhibits oscillations which may change significantly upon increasing the number of wire atoms. Our numerical studies reveal that the conductance depends strongly on whether or not the substrate electrons are localized. As a further ubiquitous feature, we observe the formation of charge oscillations.