Case for a U(1)π Quantum Spin Liquid Ground State in the Dipole-Octupole Pyrochlore Ce

Thermal spin dynamics of Kitaev magnets -- scattering continua and magnetic field induced phases within a stochastic semiclassical approach

“…In this work we use white noise and rescale the numerically calculated dynamic structure factor S (ω, k) by a factor of βω/(1 − e −βω ) reducing the spectral weight at small frequencies for low temperatures. This way of correcting shortcomings of a purely classical calculation has recently been shown to give quantitatively similar results as the 1/S Holstein-Primakoff expansion, with qualitative agreement to INS experiments on frustrated three-dimensional magnets [62][63][64].…”

“…The general lesson of the present as well as previous [60,[62][63][64] works is that the finite temperature response of a frustrated classical magnet can look surprisingly similar to the one expected from fractionalized excitations in a QSL at zero temperature. This makes the unambiguous observation of quantum fractionalization a challenging task for scattering experiments (at least if they are not performed at temperatures several orders of magnitude below the magnetic exchange scales).…”

“…The key idea is to match the definition of the classical and quantum fluctuation-dissipation relations of the spin structure factor (see Appendix H of Ref. [64] for a recent discussion). In this work we use white noise and rescale the numerically calculated dynamic structure factor S (ω, k) by a factor of βω/(1 − e −βω ) reducing the spectral weight at small frequencies for low temperatures.…”

“…Only the low frequency response differs as it is governed by quantum selection rules associated with fractionalized flux excitations [19,61]. Moreover, semiclassical dynamics of thermally disordered frustrated magnets have recently been shown to capture the INS response of other QSL candidates like NaCaNi 2 F 7 [62], MgCr 2 O 4 [63], Ce 2 Zr 2 O 7 [64] or the Γ-model [65]. Thus, our work similarly addresses more general questions beyond the concrete example of α−RuCl 3 , namely understanding the broad INS scattering continua of frustrated magnets, and diagnosing genuine quantum fractionalization signatures.…”

Bragg diffraction by a magnetic all-in–all-out configuration with application to a cubic cerium pyrochlore oxide

“…Symmetry-informed calculations of scattering amplitudes for beams of neutrons and x rays tuned in energy to the atomic resonance of magnetic ions are reported in our submission. In the model, magnetic ions decorate a lattice (space group O 7 h or F d 3m) that hosts a noncollinear all-in-all-out (AIAO) motif of magnetic dipoles depicted in Fig. 1, where dipoles point toward or away from the center of each tetrahedron.…”