Eur. Phys. J. B 44, 373-380 (2005)
https://doi.org/10.1140/epjb/e2005-00136-1

Proximity effect gaps in S/N/FI structures

¹ Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520, USA
² Kavli Institute of NanoScience Delft, Delft University of Technology, Lorentzweg 1, 2628 CJ, Delft, The Netherlands

Corresponding author: ^a daniel.huertas-hernando@yale.edu

Received: 7 September 2004
Revised: 25 January 2005
Published online: 28 April 2005

Abstract

We study the proximity effect in hybrid structures consisting of superconductor and ferromagnetic insulator separated by a normal diffusive metal (S/N/FI structures). These stuctures were proposed to realize the absolute spin-valve effect. We pay special attention to the gaps in the density of states of the normal part. We show that the effect of the ferromagnet is twofold: It not only shifts the density of states but also provides suppression of the gap. The mechanism of this suppression is remarkably similar to that due to magnetic impurities. Our results are obtained from the solution of one-dimensional Usadel equation supplemented with boundary conditions for matrix current at both interfaces.