Thermal stability of pair density wave in a $d$-wave altermagnetic superconductor

TL;DR

This paper demonstrates that altermagnetism in a two-dimensional $d$-wave superconductor stabilizes a thermally robust pair density wave state, with potential experimental signatures, using advanced Monte Carlo simulations.

Contribution

It reveals that altermagnetism can stabilize a finite-momentum PDW state at finite temperatures beyond mean-field approximations.

Findings

Altermagnetism stabilizes a PDW state without external fields.

The PDW state remains stable at finite temperatures.

Thermodynamic and spectroscopic signatures of the PDW are identified.

Abstract

We study finite-momentum superconductivity in a two-dimensional $d$-wave altermagnetic superconductor using a non-perturbative Monte Carlo approach beyond mean-field theory. We show that altermagnetism stabilizes a pair density wave (PDW) state without external magnetic fields and enables its survival at finite temperatures with robust phase coherence. Our results establish altermagnetism as a promising route to realizing thermally stable PDW superconductivity and identify clear thermodynamic and spectroscopic signatures.