Proximate Kitaev quantum spin liquid behaviour in a honeycomb magnet.

By Arnab Banerjee, C. Bridges, J.-Q. Yan, A. Aczel, L. Li, M. Stone, G. Granroth, M. Lumsden, Yuen Yiu, J. Knolle and 6 more. Nature Materials, 2015

915 citations recorded by the source corpus.

Quantum spin liquids (QSLs) are topological states of matter exhibiting remarkable properties such as the capacity to protect quantum information from decoherence. Whereas their featureless ground states have precluded their straightforward experimental identification, excited states are more revealing and particularly interesting owing to the emergence of fundamentally new excitations such as Majorana fermions. Ideal probes of these excitations are inelastic neutron scattering experiments. These we report here for a ruthenium-based material, α-RuCl3, continuing a major search (so far concentrated on iridium materials) for realizations of the celebrated Kitaev honeycomb topological QSL. Our measurements confirm the requisite strong spin-orbit coupling and low-temperature magnetic order matching predictions proximate to the QSL. We find stacking faults, inherent to the highly two-dimensional nature of the material, resolve an outstanding puzzle. Crucially, dynamical response measurements above interlayer energy scales are naturally accounted for in terms of deconfinement physics expected for QSLs. Comparing these with recent dynamical calculations involving gauge flux excitations and Majorana fermions of the pure Kitaev model, we propose the excitation spectrum of α-RuCl3 as a prime candidate for fractionalized Kitaev physics.

Subfields: Condensed Matter Physics, Electrical and Electronic Engineering

View Paper: https://www.semanticscholar.org/paper/509b5ffaec418c1520ab71ebe1a2aa7e9a21304c

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Condensed Matter Physics

1. Simon Trebst
2. C. Hickey
3. J. Knolle
4. I. Kimchi
5. S. Nagler
6. Roderich Moessner
7. M. McGuire
8. M. Hermanns

In Electrical and Electronic Engineering

1. Simon Trebst
2. C. Hickey
3. M. McGuire
4. D. Mandrus

Citations in the corpus

• The physics of quantum materials (2017, neutral): “114).”
• Crystal and Magnetic Structures in Layered, Transition Metal Dihalides and Trihalides (2017, background): “This can give rise to a quantum spin liquid ground state, in which fluctuations prevent magnetic order even at very low temperature, and in which particulary exotic magnetic excitations are predicted [13,145,146].”
• Excitations in the field-induced quantum spin liquid state of α-RuCl3 (2017, methodology): “consistent with previous measurements [3, 12, 13].”
• Physics of the Kitaev Model: Fractionalization, Dynamic Correlations, and Material Connections (2017, background): “First, results on RuCl3 from powder scattering revealed the presence of a broad high frequency low wavenumber magnetic continuum which is insensitive to cooling through the AFM transition below which only the very low frequency response develops sharp spin-wave-like excitations [29].”
• Kitaev materials (2017, background): “Below TN = 7 K pristine α-RuCl3 exhibits zig-zag magnetic ordering (similar to that of Na2IrO3) confirmed in various experimental probes including neutron [126, 127] and X-ray [128, 124] diffraction experiments, inelastic neutron scattering on polycrystalline [116] and single-crystal [125] samples a”
• Probing and controlling magnetic states in 2D layered magnetic materials (2019, neutral): “RuCl 3 has attracted attention because of its potential in realizing the Kitaev spin liquid model 67,68 .”