Magnetoelectric effect in the helical state of a superconductor/ferromagnet bilayer

TL;DR

This paper investigates the microscopic origins of the helical superconducting state in a superconductor/ferromagnet bilayer with spin-splitting and Rashba spin-orbit coupling, revealing mechanisms for controlling magnetization via supercurrents.

Contribution

It provides an exact solution to the Gor'kov equations for this system, enabling a comprehensive analysis of thermodynamic properties and the control of magnetization through supercurrents.

Findings

Exact Gor'kov solution for the system's thermodynamics

Control of magnetization using supercurrents in dc and ac regimes

Identification of the diode effect related to spin-orbit interaction

Abstract

We study the microscopic mechanism of nucleation of the helical superconducting state maintained by a spin-splitting field and weak Rashba spin-orbit coupling in a 2D superconductor/ferromagnet system and present an exact solution for the Gor'kov equations, which provides a full description of the thermodynamic properties of the system under consideration. This permits us to obtain the Ginzburg-Landau expansion and use it to analyze the possibility of controlling magnetization using the transport supercurrent in both dc and quasistatic ac regimes. We show that these properties are related to the manifestation of the diode effect in superconducting systems with spin-orbit interaction.