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arXiv · 2601.19343

Probing multipolar order in the candidate altermagnet MnF$_2$ through the elastocaloric effect under strain

Rahel Ohlendorf·Luca Buiarelli·Hilary M. L. Noad·Andrew P. Mackenzie·Rafael M. Fernandes·Turan Birol·Jörg Schmalian·Elena Gati
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Abstract

Altermagnets break a combination of time-reversal and rotational symmetries without generating a net magnetization. As such, the order parameter of $d$-wave altermagnets has the same symmetry as magnetic multipoles, and couples to the product of a magnetic field and uniaxial strain. We combine elastocaloric experiments, free-energy modeling, and first-principles calculations on MnF$_2$ to establish a thermodynamic probe of the predicted finite-temperature altermagnetic critical point. These results pave the way to explore altermagnetic quantum criticality in $d$-wave materials and beyond.

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Rahel Ohlendorf, Luca Buiarelli, Hilary M. L. Noad, Andrew P. Mackenzie, Rafael M. Fernandes, Turan Birol, Jörg Schmalian, Elena Gati. 2026-01-27. Probing multipolar order in the candidate altermagnet MnF$_2$ through the elastocaloric effect under strain. https://doi.org/10.1103/svrz-315w

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