Has emergent quantum electrodynamics been observed in a quantum spin ice? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
Has emergent quantum electrodynamics been observed in a quantum spin ice?
Plain · changed
Revision 1: Quantum spin ice should host three kinds of emergent particles: photons, electric-like spinons and magnetic monopoles. Cerium pyrochlores such as Ce2Zr2O7 show signs of these, but alternative explanations are not fully excluded.
Revision 2: Quantum spin ice should host three kinds of emergent particles: photons, electric-like spinons and magnetic monopoles. Cerium pyrochlores such as $\mathrm{Ce_2Zr_2O_7}$ show signs of these, but alternative explanations are not fully excluded.
Precise · changed · core
Revision 1: In Ce2Zr2O7, Ce2Sn2O7 and Ce2Hf2O7 (dipolar-octupolar doublets), establish the $\mathrm{U}(1)$ quantum spin liquid through its distinct signatures: a gapless linearly dispersing transverse photon ($C \sim T^{3}$ well below the photon bandwidth), a spinon continuum, and their predicted spectral weights. An answer is a fit of thermodynamic and neutron data by quantum spin ice theory with independently fixed exchange parameters that excludes classical or disorder-driven alternatives.
Revision 2: In $\mathrm{Ce_2Zr_2O_7}$, $\mathrm{Ce_2Sn_2O_7}$ and $\mathrm{Ce_2Hf_2O_7}$ (dipolar-octupolar doublets), establish the $\mathrm{U}(1)$ quantum spin liquid through its distinct signatures: a gapless linearly dispersing transverse photon ($C \sim T^{3}$ well below the photon bandwidth), a spinon continuum, and their predicted spectral weights. An answer is a fit of thermodynamic and neutron data by quantum spin ice theory with independently fixed exchange parameters that excludes classical or disorder-driven alternatives.
Settled by
Polarized neutron scattering below $0.05\,\mathrm{K}$ resolving the low-energy photon mode and heat capacity showing the $T^3$ term, both matched to quantum Monte Carlo of the fitted XYZ model.
Kind
phenomenon
Answer type
identification
References
(empty)
Literature status
partially-resolved
Status note · changed
Revision 1: Gao et al. (Nature Physics 2025) reported neutron and thermodynamic evidence for emergent photons and spinons in Ce2Zr2O7, interpreted as a pi-flux quantum spin ice.
Revision 2: Gao et al. (Nature Physics 2025) reported neutron and thermodynamic evidence for emergent photons and spinons in $\mathrm{Ce_2Zr_2O_7}$, interpreted as a pi-flux quantum spin ice.
Posed since
2004

Decisions