Skip to main content
Article thumbnail
Location of Repository

Nonequilibrium Spin-transfer Torque in SFNFS Junctions

By Erhai Zhao

Abstract

Spin-polarized current passing through a ferromagnet can transfer spin angular momentum to the ferromagnet and exert a torque on the magnetic moment [1, 2]. This mechanism offers unique opportunities to manipulate the magnetic state of nanomagnets. Experimentally spin-transfer torque driven magnetization precession and magnetization reversal have been observed in magnetic multilayers [3, 4]. A well studied multilayer system is the magnetic nanopillar which consists of a ferromagnetnormal metal-ferromagnet (FNF) trilayer connected to normal metal electrodes. The typical thickness of each layer is several nm, and the diameter of the pillar is of the order of 50 nm [4]. When sandwiched between superconducting electrodes, the FNF trilayer can mediate finite Josephson coupling to form a SFNFS Josephson junction [5]. In such junctions, scattering of quasiparticle at the magnetic interfaces is sensitive to the phase shift in each F layer as well as the condensate phase difference φ across the junction. This indicates the spin momentum transfer between the quasiparticles and ferromagnets can be tuned by varying φ. Waintal and Brouwer calculated the phase-sensitive equilibrium torque in SFNFS junctions [6]. They also showed the nonequilibrium torque in NFNFS junctions acquires novel features, e.g. it can favor perpendicular configuration of the two moments [7]

Year: 2006
OAI identifier: oai:CiteSeerX.psu:10.1.1.306.2464
Provided by: CiteSeerX
Download PDF:
Sorry, we are unable to provide the full text but you may find it at the following location(s):
  • http://citeseerx.ist.psu.edu/v... (external link)
  • http://arxiv.org/pdf/cond-mat/... (external link)
  • Suggested articles


    To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.