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Title: Zero-flux or pi-flux quantum spin ice in cerium pyrochlores?
Plain: Quantum spin ice comes in two versions, labeled zero-flux and pi-flux, that differ in how emergent charges feel the internal magnetic field. Which version each cerium compound realizes depends on the signs of its exchange couplings, which are still debated.
Precise: For Ce2Zr2O7, Ce2Sn2O7 and Ce2Hf2O7 described by the dipolar-octupolar Hamiltonian H = sum_<ij> [J_x tau^x_i tau^x_j + J_y tau^y_i tau^y_j + J_z tau^z_i tau^z_j + J_xz (tau^x_i tau^z_j + tau^z_i tau^x_j)], determine the exchange parameters and the sign of the dominant transverse coupling that fixes the zero-flux or $\pi$-flux $U(1)$ phase, and confirm it by the predicted spinon-continuum structure. An answer is the classification per compound with fitted parameters.
Settled by: Global fits of neutron spectra, heat capacity and magnetization in field to the XYZ model, compared with the distinct spinon spectra of each flux phase.
Kind: well-posed
Answer type: classification
References: (empty)
Literature status: contested
Status note: Gao et al. (2025) classify Ce2Zr2O7 as pi-flux; parameter fits differ across groups and compounds.
Posed since: (empty)