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Title: Breakdown of magnons in a strongly spin-orbital coupled magnet

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 α-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 anharmonicity that naturally occurs in such materials. This scenario fully explains the observed inelastic magnetic response of α-RuCl 3 and reveals the presence of nontrivial excitations in such materials extending well beyond the Kitaev state.

Authors:
ORCiD logo [1];  [1];  [2];  [2]; ORCiD logo [3];  [1]
  1. Goethe-Universität Frankfurt (Germany)
  2. Univ. of California, Irvine, CA (United States)
  3. Université de Cergy-Pontoise (France)
Publication Date:
Research Org.:
Univ. of California, Irvine, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1499928
Grant/Contract Number:  
FG02-04ER46174
Resource Type:
Accepted Manuscript
Journal Name:
Nature Communications
Additional Journal Information:
Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 2041-1723
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Winter, Stephen M., Riedl, Kira, Maksimov, Pavel A., Chernyshev, Alexander L., Honecker, Andreas, and Valentí, Roser. Breakdown of magnons in a strongly spin-orbital coupled magnet. United States: N. p., 2017. Web. doi:10.1038/s41467-017-01177-0.
Winter, Stephen M., Riedl, Kira, Maksimov, Pavel A., Chernyshev, Alexander L., Honecker, Andreas, & Valentí, Roser. Breakdown of magnons in a strongly spin-orbital coupled magnet. United States. doi:10.1038/s41467-017-01177-0.
Winter, Stephen M., Riedl, Kira, Maksimov, Pavel A., Chernyshev, Alexander L., Honecker, Andreas, and Valentí, Roser. Fri . "Breakdown of magnons in a strongly spin-orbital coupled magnet". United States. doi:10.1038/s41467-017-01177-0. https://www.osti.gov/servlets/purl/1499928.
@article{osti_1499928,
title = {Breakdown of magnons in a strongly spin-orbital coupled magnet},
author = {Winter, Stephen M. and Riedl, Kira and Maksimov, Pavel A. and Chernyshev, Alexander L. and Honecker, Andreas and Valentí, Roser},
abstractNote = {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 α-RuCl3, 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 anharmonicity that naturally occurs in such materials. This scenario fully explains the observed inelastic magnetic response of α-RuCl3 and reveals the presence of nontrivial excitations in such materials extending well beyond the Kitaev state.},
doi = {10.1038/s41467-017-01177-0},
journal = {Nature Communications},
number = 1,
volume = 8,
place = {United States},
year = {2017},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
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Citation Metrics:
Cited by: 46 works
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Figures / Tables:

Fig. 1 Fig. 1 : From material to model. Within the honeycomb ab-layer of $α$-RuCl3 are illustrated the RuCl6 octahedra, magnetic zigzag ordering pattern, and definition of the underlying magnetic interactions. Crystal axes are labeled with respect to the C2/m structure

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    Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.