Site web ESPCI
Jeudi 16 Janvier 2014, 14h
Amphi Holweck, Esc C, 1ème etage
Long Range Triplet Josephson Current and Novel
0-π Transition in Tunable Domain Walls
Andreas Bill
Dept. of Physics & Astronomy, California State University, Long Beach, CA 90840, SA
This talk presents one aspect of the coexistence of superconducting and magnetic phases in proximity systems in the wide dirty limit. We discuss the appearance of a long range triplet component (LRTC) with non-zero spin projection (Sz=±1) of the order parameter when singlet Cooper pairs penetrate an inhomogeneous magnetic material. We show using an analytically derived domain wall of an exchange spring how the LRTC emerges and can be tuned with the twisting of the magnetization [1]. We also introduce a new kind of Josephson current reversal, the triplet 0 − π transition that can be observed in one and the same system either by tuning the domain wall or by varying temperature. Finally, we show how the LRTC may be manipulated to produce a conventional current reversal in junctions made of 5n magnetic multilayers (n an integer).
[1] Thomas E. Baker, Adam Richie-Halford, and Andreas Bill, arXiv:1310.6632.
We gratefully acknowledge the support of the National Science Foundation (DMR-0907242), the Army Research Laboratory and the Research Corporation.