Superconductivity as a Probe of Altermagnetism: Critical Temperature, Field, and Current

TL;DR

This paper investigates how coexisting altermagnetic and superconducting orders in thin films lead to distinctive fourfold anisotropies in critical properties, providing experimental signatures of altermagnetism.

Contribution

It introduces a theoretical framework using Ginzburg-Landau theory to analyze the interplay between altermagnetism and superconductivity in thin films under magnetic fields.

Findings

Fourfold anisotropies in critical temperature, field, and current due to altermagnetism

Characteristic signatures detectable in experiments

Insights into superconductor/altermagnetic heterostructures

Abstract

We study thin films that host coexisting collinear $d$-wave altermagnetic and superconducting orders in the presence of an external magnetic field that fully penetrates the films. We use the Ginzburg-Landau functional to analyze the response of the films to magnetic fields and an in-plane supercurrent. We demonstrate that the interplay between superconductivity and altermagnetism induces characteristic fourfold anisotropies in the critical temperature, parallel critical field, and critical current density of the films. These results establish experimentally accessible signatures of altermagnetism in superconducting films and in superconductor/altermagnetic insulator heterostructures.