Nature of the low energy excitations in the short range ordered region of Cs$_2$CuCl$_4$ as revealed by $^{133}$Cs NMR
(2012)
Spin waves and revised crystal structure of honeycomb iridate Na2IrO3
(2012)
Spin waves and revised crystal structure of honeycomb iridate Na2IrO3
ArXiv 1202.1268 (2012)
Abstract:
We report inelastic neutron scattering measurements on Na2IrO3, a candidate for the Kitaev spin model on the honeycomb lattice. We observe spin-wave excitations below 5 meV with a dispersion that can be accounted for by including substantial further-neighbor exchanges that stabilize zig-zag magnetic order. The onset of long-range magnetic order below 15.3 K is confirmed via the observation of oscillations in zero-field muon-spin rotation experiments. Combining single-crystal diffraction and density functional calculations we propose a revised crystal structure model with significant departures from the ideal 90 deg Ir-O-Ir bonds required for dominant Kitaev exchange.Quantum criticality in an Ising chain: experimental evidence for emergent E8 symmetry
(2011)
Anomalous high-energy spin excitations in the high-Tc superconductor-parent antiferromagnet Laâ‚‚CuOâ‚„.
Phys Rev Lett 105:24 (2010) 247001