Origin of magnetic-domain imbalance

Determine why a single time-reversal magnetic domain predominates in the Mn antiferromagnetic phase of EuMnSb₂, despite the two time-reversal domains having the same energy.

Background

Spherical neutron polarimetry revealed nonzero off-diagonal polarization-matrix elements, indicating a substantial imbalance between magnetic domains in the Mn antiferromagnetic structure. The refinements showed that the magnetic phase is almost entirely composed of one of the two time-reversal domains, even though the two domains should be energetically degenerate. The physical origin of this domain selection is not resolved and is not essential to the determination of the magnetic structure.

References

It is not clear why a single magnetic domain formed given that the two time-reversal domains should have the same energy. Since its origin is unclear and not central to the magnetic structure determination, we leave this as an open question.

— Resolving the Magnetic Ground State and Field-Induced Transitions in Magnetic Dirac Semimetal Candidate EuMnSb$_2$  (2608.16724 - Chiu et al., 17 Aug 2026) in Section 3, discussion of the (210) polarization matrix

These observations raise two distinct questions. For a given domain configuration, what is the mechanism by which $B_\parallel$ near zero produces excess resistance? And how is the domain configuration itself set by the magnetic field present when the ordered state forms?

— Metastable magnetic domains and the anomalous $B_\parallel=0$ resistance peak in twisted double bilayer graphene  (2608.25263 - Gao et al., 26 Aug 2026) in Section Discussion, subsection “Domain configuration”