Frustration-induced multiferroicity in hauerite MnS2
arXiv:2610.01990
Vilmos Kocsis, Harish K. Singh, Kranthi K. Bestha, Yaqian Guo, Maxim Mostovoy, Jeroen van den Brink, Oleg Janson
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Below 48 K, antiferromagnetic order in pyrite MnS₂ doubles the cell, breaks inversion, and — via dipoles on S₂ dimers — yields a type-II ferroelectric polarization up to 360 μC/m².
Read free explainer →Pyrite-type mineral hauerite MnS$_2$ is a magnetic insulator with localized $S=\frac52$ moments. Below 48 K, it develops a collinear antiferromagnetic order, accompanied by unit-cell doubling and breaking the inversion symmetry. We demonstrate that the latter gives rise to a ferroelectric polarization of up to 360 $μ$C/m$^2$ rendering MnS$_2$ a type-II multiferroic. Microscopically, the electronic polarization originates from S$_2$ dimers that acquire a dipole moment induced by the frustrated magnetic ordering of neighboring Mn sites. We show that time-reversal symmetry leaves ferroelectric domains intact, and that domain switching necessitates overcoming a high energy barrier set by the magnetic exchange energy scale.