Manipulating Magnetic Moments by Superconducting Currents

TL;DR

This paper demonstrates that superconducting currents in a Rashba spin-orbit coupled superconductor can generate and manipulate magnetic anisotropy and magnetic moments of atomic clusters, offering a potentially efficient low-temperature magnetization control method.

Contribution

It introduces a novel mechanism for manipulating magnetic moments using superconducting currents influenced by spin-orbit coupling, surpassing traditional methods at low temperatures.

Findings

Superconducting currents induce magnetic anisotropy comparable to crystal field effects.

Transport currents can control the magnetic moment direction via effective magnetic fields.

Method offers advantages over spin-transfer torque at low temperatures.

Abstract

We show that the interaction between a superconducting order parameter and the magnetic moment of an atomic cluster in a two-dimensional s-wave superconductor with Rashba spin-orbit coupling generates magnetic anisotropy that can be stronger or comparable to the magnetic anisotropy due to the crystal field and the shape of the cluster. Transport current through the superconductor produces the effective magnetic field acting on the cluster's magnetic moment. The direction of the effective field depends on the direction of the current, thus allowing one to manipulate the magnetic moment by the superconducting current. Due to the large density of the superconducting current this method of magnetization reversal can be more advantageous at low temperatures than the spin-transfer torque method that requires a large spin-polarized current through a normal metal.