Eur. Phys. J. B (2012) 85: 196
https://doi.org/10.1140/epjb/e2012-30133-0

Regular Article

Metamorphosis and taxonomy of Andreev bound states

Laboratoire de Physique des Solides, Université Paris-Sud, Bât. 510, 91405 Orsay, France
Institut de Physique Théorique, CEA/Saclay, CNRS, URA 2306, Orme des Merisiers, 91191 Gif-sur-Yvette, France

^a e-mail: cristina.bena@u-psud.fr

Received: 14 February 2012
Received in final form: 21 March 2012
Published online: 18 June 2012

Abstract

We analyze the spatial and energy dependence of the local density of states in a SNS junction. We model our system as a one-dimensional tight-binding chain which we solve exactly by numerical diagonalization. We calculate the dependence of the Andreev bound states on position, phase difference, gate voltage, and coupling with the superconducting leads. Our results confirm the physics predicted by certain analytical approximations, but reveal a much richer set of phenomena beyond the grasp of these approximations, such as the metamorphosis of the discrete states of the normal link (the normal bound states) into Andreev bound states as the leads become superconducting.