Proximity-effect–assisted decay of spin currents in superconductors

¹  Department of Physics, Norwegian University of Science and Technology - NO-7491 Trondheim, Norway
²  Centre for Advanced Study at the Norwegian Academy of Science and Letters Drammensveien 78, NO-0271 Oslo, Norway
³  Kavli Institute of NanoScience, Delft University of Technology - 2628 CJ Delft, The Netherlands, EU
⁴  Department of Physics, University of Konstanz - D-78457 Konstanz, Germany, EU
⁵  Department of Physics and Astronomy, University of California - Los Angeles, CA 90095, USA

Corresponding author: janpette@tf.phys.ntnu.no

Received: 20 June 2008
Accepted: 28 October 2008

Abstract

The injection of pure spin current into superconductors by the dynamics of a ferromagnetic contact is studied theoretically. Taking into account the suppression of the order parameter at the interfaces (inverse proximity effect) and the energy-dependence of spin-flip scattering, we determine the temperature-dependent ferromagnetic resonance linewidth broadening. Our results compare well with recent experiments in Nb|permalloy bilayers (Bell C. et al., Phys. Rev. Lett., 100 (2008) 047002).