Determine the interaction energy scales governing kagome-plane fluctuations

Determine the exact interaction energy scales in Pr₂Zr₂O₇ that govern the high-frequency fluctuations of magnetic moments in the kagome planes under a magnetic field parallel to [111].

Background

The Raman measurements identify fluctuations of Pr³⁺ moments in the kagome planes persisting up to magnetic fields of 14 T, with a characteristic frequency of approximately 2 meV. This energy scale is unexpectedly large compared with the interaction scales generally anticipated for Pr₂Zr₂O₇, which are often estimated to be of order 1 K. The paper notes that the precise interaction values are not established, leaving unresolved which exchange, quadrupolar, or related couplings can account for the observed dynamics.

References

The fluctuations which extend to such high magnetic fields suggest high values of the quadrupolar interactions. There was recently a theoretical proposal that quadrupolar component can exceed exchange scattering, and result in quantum spin liquid states beyond quantum spin ice, assumed previously for Pr$_2$Zr$_2$O$_7$. It would be interesting to consider how our result is related to this new framework.

— Raman Scattering Evidence for Fluctuating Kagome-Plane Moments in $\mathrm{B} \parallel [111]$ in Pr$_2$Zr$_2$O$_7$ pyrochlore  (2609.24696 - Xu et al., 21 Sep 2026) in Discussion