1. Breakdown of magnons in a strongly spin-orbital coupled magnet
- Author
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Kira Riedl, P. A. Maksimov, Andreas Honecker, Stephen M. Winter, Alexander Chernyshev, Roser Valentí, Institut für Theoretische Physik [Frankfurt am Main] (ITP), Goethe-Universität Frankfurt am Main, Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089), and Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)
- Subjects
Science ,Mathematics::General Topology ,FOS: Physical sciences ,General Physics and Astronomy ,02 engineering and technology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,Condensed Matter - Strongly Correlated Electrons ,Computer Science::Emerging Technologies ,0103 physical sciences ,ddc:530 ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,lcsh:Science ,010306 general physics ,ComputingMilieux_MISCELLANEOUS ,Physics ,Mathematics::Combinatorics ,Multidisciplinary ,Strongly Correlated Electrons (cond-mat.str-el) ,Spins ,Continuum (measurement) ,Condensed matter physics ,Magnon ,Anharmonicity ,General Chemistry ,021001 nanoscience & nanotechnology ,Magnet ,Quasiparticle ,lcsh:Q ,Quantum spin liquid ,cond-mat.str-el ,0210 nano-technology ,Excitation - Abstract
The description of quantized collective excitations stands as a landmark in the quantum theory of condensed matter. A prominent example occurs in conventional magnets, which support bosonic magnons - quantized harmonic fluctuations of the ordered spins. In striking contrast is the recent discovery that strongly spin-orbital coupled magnets, such as $\alpha$-RuCl$_3$, may display a broad excitation continuum inconsistent with conventional magnons. Due to incomplete knowledge of the underlying interactions unraveling the nature of this continuum remains challenging. The most discussed explanation refers to a coherent continuum of fractional excitations analogous to the celebrated Kitaev spin liquid. Here we present a more general scenario. We propose that the observed continuum represents incoherent excitations originating from strong magnetic anharmoniticity that naturally occurs in such materials. This scenario fully explains the observed inelastic magnetic response of $\alpha$-RuCl$_3$ and reveals the presence of nontrivial excitations in such materials extending well beyond the Kitaev state., Comment: Final version; supplemental information included
- Published
- 2017