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Josephson effect in supercondutor/ferromagnetic semiconductor/superconductor junctions

Authors :
Y.C. Tao
Source :
Physica B: Condensed Matter. 403:95-102
Publication Year :
2008
Publisher :
Elsevier BV, 2008.

Abstract

Using a general expression for dc Josephson current, we study the Josephson effect in ballistic superconductor (SC)/ferromagnetic semiconductor (FS)/SC junctions, in which the mismatches of the effective mass and Fermi velocity between the FS and SC, spin polarization P in the FS, as well as strengths of potential scattering Z at the interfaces are included. It is shown that in the coherent regime, the oscillatory dependences of the maximum Josephson current on the FS layer thickness L and Josephson current on the macroscopic phase difference φ for the heavy and light holes, resulting from the spin splitting energy gained or lost by a quasiparticle Andreev-reflected at the FS/SC interface, are much different due to the different mismatches in the effective mass and Fermi velocity between the FS and the SC, which is related to the crossovers between positive (0) and negative ( π ) couplings or equivalently 0 and π junctions. Also, we find that, for the same reason, Z and P are required not to surpass different critical values for the Josephson currents of the heavy and light holes. Furthermore, it is found that, for the dependence of the Josephson current on φ , regardless of how L , Z , and P change, the Josephson junctions do not transit between 0 and π junctions for the light hole.

Details

ISSN :
09214526
Volume :
403
Database :
OpenAIRE
Journal :
Physica B: Condensed Matter
Accession number :
edsair.doi...........6f78d57f3514074c4500c65f5e915033