Magnetoanisotropic Josephson effect due to interfacial spin-orbit fields in superconductor/ferromagnet/superconductor junctions

Abstract

We study theoretically the effects of interfacial Rashba and Dresselhaus spin-orbit coupling in superconductor/ferromagnet/superconductor (S/F/S) Josephson junctions-with allowing for tunneling barriers between the ferromagnetic and superconducting layers-by solving the Bogoljubov-de Gennes equation for realistic heterostructures and applying the Furusaki-Tsukada technique to calculate the electric current at a finite temperature. The presence of spin-orbit couplings leads to out-of-plane and in-plane magnetoanisotropies of the Josephson current, which are giant in comparison to current magnetoanisotropies in similar normal-state ferromagnet/normal metal (F/N) junctions. Especially huge anisotropies appear in the vicinity of 0-π transitions, caused by the exchange-split bands in the ferromagnetic metal layer. We also show that the direction of the Josephson critical current can be controlled (inducing 0-π transitions) by the strength of the spin-orbit coupling and, more crucial, by the orientation of the magnetization. Such a control can bring new functionalities into Josephson junction devices.

Long-ranged triplet supercurrent in a single in-plane ferromagnet with spin-orbit coupled contacts to superconductors

“…Therefore, it would be desirable to identify a setup where the LRTs can be tuned with a sole in-plane variation of the magnetization to minimize the stray field effect on the superconductor itself. This would be a different result than previous works [13,14,[16][17][18][19][20] that have considered how to control the supercurrent via magnetization in Josephson contacts with spin-orbit coupling. A long-ranged supercurrent was predicted in Ref.…”

Enhanced spin-triplet pairing in magnetic junctions with s -wave superconductors

“…While we employ a simple approach which naturally suggests a number of generalizations, from inclusion of the self-consistent pair potential, finite B-fields, study of critical temperature, or more complex barrier description [42][43][44][45][46][47], its transparency already reveals several important trends and can support peculiar experimental observation of a giant MAAR [40]. Our implications for enhanced triplet pairing and MAAR detection could also be relevant for two-dimensional materials, as supported by the work in Refs.…”

Supercurrent vortex pinball via a triplet Cooper pair inverse Edelstein effect

“…In the study of a 1D Josephson junction with spin-orbit coupling, it was recently discovered that the critical current varies greatly with the direction of an applied exchange field, even creating 0-π transitions 8,13 . It is therefore reasonable to presume that the current density distribution becomes nontrivial.…”

“…If the exchange field is spatially varying, or the system contains spin-orbit coupling, the triplet Cooper pairs may rotate between different triplet states where the electron spins are parallel, making tunable superconducting spin transport possible [2][3][4] . In light of this discovery, the effect of spin-orbit coupling on proximitized materials has recently been investigated in several works [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] . In this paper, we consider a spin-orbit coupled superconducting hybrid which is found to display novel, inherently two-dimensional, physical phenomena which are hidden in effective one-dimensional models.…”