Spin disorder and electronic correlations in altermagnetic CrSb and MnTe investigated within the disordered local moment picture
Date:
Contributed talk at the 2026 CCP9 Conference and Community Meeting. CCP9 is the UK’s electronic structure network. N.B. Due to illness, I was unable to attend the conference and this abstract was presented on my behalf by my co-author, Nabil Menai.
Abstract
So called ‘altermagnets’ are an intriguing class of magnetically ordered material in which there is a net zero magnetisation, but in which electronic bands are not spin-degenerate on account of the intrinsic symmetries of the underlying crystal structure. In the zero-temperature limit, the atomic magnetic moments (or ‘spins’) will be arranged in a perfectly ordered, collinear structure. However, at any finite temperature, thermal fluctuations will cause the spins to deviate from this pristine arrangement. Above some critical temperature (the Néel temperature), long-range magnetic order disappears entirely, and the material transitions to a paramagnetic state. Here, we will present results of ab initio electronic structure calculations performed on two prototypical altermagnets: CrSb, which is metallic; and MnTe, which is semiconducting. We demonstrate that the magnetic phase transition in both materials is well-described by disordered local moment (DLM) theory [1-3] in combination with an appropriate choice of exchange-correlation functional, and describe in detail how site-diagonal spin disorder induces changes to calculated band structures. We provide preliminary estimates for the Néel temperature of both materials, and also discuss implications for temperature-dependent transport properties.
References
[1] B. L. Győrffy et al., J. Phys. F: Met. Phys. 15, 1337 (1985).
[2] J. Staunton et al., J. Phys. F: Met. Phys. 15, 1387 (1985).
[3] I. D. Hughes et al., New J. Phys. 10, 063010 (2008).