Sticky Goos-Hänchen effect at normal/superconductor interface

¹ Max Planck Institute for the Physics of Complex Systems - Nöthnitzer Str. 38, D01187 Dresden, Germany, EU
² Department of Mathematics and Information Sciences, Northumbria University - Newcastle Upon Tyne, NE1 8ST, UK, EU
³ Vinca Institute of Nuclear Sciences, University of Belgrade - P. O. Box 522, 11001 Belgrade, Serbia
⁴ Toshiba Telecommunications Research Laboratory - 32 Queens Square, BS1 4ND, Bristol, UK, EU

Received: 8 May 2013
Accepted: 24 July 2013

Abstract

We study the quantum Goos-Hänchen (GH) effect for wave-packet dynamics at a normal/superconductor (NS) interface. We find that the effect is amplified by a factor , with E_F the Fermi energy and Δ the gap. Interestingly, the GH effect appears only as a time delay without any lateral shift, and the corresponding delay length is about , with the Fermi wavelength. This makes the NS interface “sticky” when , since typically GH effects are of wavelength order. This “sticky” behavior can be further enhanced by a resonance mode in the NSNS interface. Finally, for a large Δ, the resonance-mode effect makes a transition from the Andreev to the specular reflection as the width of the sandwiched superconductor is reduced.