Nature of the 530 mK thermodynamic anomaly

Determine the microscopic nature of the thermodynamic anomaly near 530 mK in TlYbS₂, including whether it corresponds to the onset of a weakly ordered magnetic state, using measurements capable of resolving the underlying magnetic order and fluctuations.

Background

TlYbS₂ exhibits a reproducible but weak and smeared specific-heat anomaly near 530 mK. The feature is tentatively associated with the onset of magnetic order, but no corresponding anomaly is resolved in the DC magnetization or AC susceptibility measurements. Consequently, the available bulk thermodynamic data do not uniquely identify the microscopic character of the low-temperature state.

The paper notes that future neutron-scattering measurements are needed to establish the nature of the weakly ordered state and to clarify the low-energy excitation spectrum. This problem is relevant because TlYbS₂ is proposed to lie near the boundary between a weakly ordered 120° state and a quantum-spin-liquid regime.

References

The absence of a corresponding feature in the magnetization and AC susceptibility data means that the nature of this anomaly cannot be established from the present bulk measurements alone.

— Low temperature thermodynamics of $S_{\mathrm{eff}}=1/2$ triangular lattice quantum spin liquid candidate TlYbS$_2$  (2609.11881 - Belbase et al., 10 Sep 2026) in Discussion; Conclusion