Das nächste Physikalische Kolloquium findet

am Montag, 9. April 2014,
um 15.30 Uhr,
im Hauptgebäude HG 0.18, statt:

Singlet-Triplet Mixing in Josephson Junctions with Rotating Magnetization

Andreas Bill

Dept. of Physics & Astronomy, California State University, Long Beach, CA 90840

Abstract

Superconductivity and magnetism may coexist and intertwine in some systems. Known for a long time is the case of antiferromagnetic superconductors. There are other, less obvious situations where the superconducting state accommodates itself with the presence of magnetism. We discuss how the singlet-triplet mixing of the order parameter allows nanoscale magnetic junctions to carry a Josephson current through very wide ferromagnets with rotating magnetization.The effect is described in terms of a cascading of singlet and triplet components and illustrated with a magnetic multilayer [1]. We show how the current can be tuned with the twisting of the magnetization. Finally, we also introduce a new kind of Josephson current reversal, the triplet 0 ? ? transition, that can be observed in one and the same system either by twisting the domain wall or by varying temperature [2].

[1] T.E. Baker, A.C. Richie-Halford, O.E. Icreverzi and A. Bill, arXiv:1403.4149,

[2] T.E. Baker, A.C. Richie-Halford, and A. Bill, arXiv:1310.6632.

We gratefully acknowledge the support of the National Science Foundation

(DMR-0907242/1309341), the Army Research Laboratory and the Research Corporation.

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