Determine the microscopic magnetic structure of the Hall-active thin-film phase

Determine the microscopic magnetic structure and propagation vector of the time-reversal-breaking, Hall-active magnetic state responsible for anomalous transport in thin Mn$_5$Si$_3$ films.

Background

Anomalous Hall and Nernst signals in thin Mn$_5$Si$_3$ films have been associated with a proposed altermagnetic phase obtained by relocating the bulk AFM2 ordering vector from the $M$ point to the zone center. The paper finds that a moderately strained, stoichiometric, bulklike Mn$_5$Si$_3$ structure does not support this interpretation, while noting that the transport data do not uniquely specify the underlying magnetic order.

Possible alternatives include a different magnetic phase, altered site occupation, off-stoichiometry, surface reconstruction, or other departures from homogeneous bulklike Mn$_5$Si$_3$. Consequently, identifying the actual microscopic realization of the Hall-active state remains an open experimental and theoretical problem.