Spin-Transfer and Exchange Torques in Ferromagnetic Superconductors

Abstract

We consider how superconducting correlations influence spin-transfer torques in ferromagnetic superconductors. It is demonstrated that there is a novel torque arising from particle-hole interference that depends on the U(1) phase associated with the superconducting order parameter. We also show that there is an equilibrium exchange torque between two ferromagnetic superconductors in contact via a normal metal mediated by Andreev states. The latter equilibrium magnetic torque is also sensitive to spin-resolved phase differences in the superconducting order parameters as well as to an externally applied phase difference.

Giant magnetoresistance and anomalous transport in phosphorene-based multilayers with noncollinear magnetization

“…Moreover, we find that the amplitudes of the torque components decay with x−1 . The penetration of the spin transfer torque into the right F region in the phosphorene-based F/N/F structure is similar to that in the ferromagnetic superconductor- [61] and graphene- based [44] spin valve structures, where the vast majority of the torque is absorbed in the interface region.…”

Boosting spintronics with superconductivity

“…The superconducting equivalent of the SOT has been studied in a number of theoretical works for different layout structures, such as Josephson junctions [102][103][104][105] and SC/FM bilayers. 106,107 We speculate that the symmetry of the system will also affect the symmetry of the torque 108 as it does for non-superconducting structures. To date, there is no experimental evidence of supercurrent-induced torques.…”

Electronic structure and Magneto-transport in MoS$_2$/Phosphorene van der Waals heterostructure

“…The torque components generate rapid oscillations. The penetration of the STT into the right ferromagnetic region in the vdW structure based heterojunction is similar to that in the ferromagnetic superconductor 30 and based spin valve of graphene 31 .…”