Possible internal crossovers within the ordered dome

Determine whether weaker internal crossovers exist within the field-induced ordered dome of Henmilite, despite the absence of a reproducible additional phase boundary in the available thermodynamic, magnetoelastic, and muon-spin-relaxation measurements.

Background

The ideal triplon-condensation picture describes a single dome-shaped field-induced ordered phase, but related ultralow-field dimer magnets can exhibit additional low- and high-field regimes within the dome. In Henmilite, the reported measurements do not resolve a reproducible internal phase boundary. The authors nevertheless leave open the possibility that weaker crossovers exist below the resolution of those experiments.