Fluctuation induced piezomagnetism in local moment altermagnets

TL;DR

This paper explores how altermagnetic order in collinear antiferromagnets leads to a fluctuation-induced piezomagnetic response and anisotropic thermal spin conductivity, revealing new physical properties driven by magnetic fluctuations.

Contribution

It demonstrates that magnetic fluctuations in altermagnets induce a piezomagnetic response and anisotropic thermal spin conductivity, a novel insight into their physical behavior.

Findings

Fluctuation-driven piezomagnetic coefficients are identified in altermagnets.

Magnetic fluctuations induce anisotropic thermal spin conductivity.

Two Heisenberg models confirm the role of temperature-induced spin fluctuations.

Abstract

It was recently discovered that, depending on their symmetries, collinear antiferromagnets may break spin degeneracy in momentum space, even in absence of spin-orbit coupling. Such systems, dubbed altermagnets, have electronic bands with a spin-momentum texture set mainly by the combined crystal-magnetic symmetry. This discovery motivates the question which novel physical properties derive from altermagnetic order. Here we show that one consequence of altermagnetic order is a fluctuation-driven piezomagnetic response. Using two Heisenberg models of d-wave altermagnets, a checkerboard one and one for rutiles, we determine the fluctuation induced piezomagnetic coefficients considering temperature induced transversal spin fluctuations. We establish in addition that magnetic fluctuations induce an anisotropic thermal spin conductivity.