Quantum Spin Dynamics Due to Strong Kitaev Interactions in the Triangular-Lattice Antiferromagnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi>CsCeSe</mml:mi></mml:mrow><mml:mrow><mml
The extraordinary properties of the Kitaev model have motivated an intense search for new physics in materials that combine geometrical and bond frustration. In this Letter, we employ inelastic neutron scattering, spin wave theory, and exact diagonalization to study the spin dynamics in the perfect triangular-lattice antiferromagnet (TLAF) CsCeSe_{2}. This material orders into a stripe phase, which is demonstrated to arise as a consequence of the off-diagonal bond-dependent terms in the spin Hamiltonian. By studying the spin dynamics at intermediate fields, we identify an interaction between the single-magnon state and the two-magnon continuum that causes decay of coherent magnon excitations, level repulsion, and transfer of spectral weight to the continuum that are controlled by the strength of the magnetic field. Our results provide a microscopic mechanism for the stabilization of the stripe phase in TLAF and show how complex many-body physics can be present in the spin dynamics in a magnet with strong Kitaev coupling even in an ordered ground state.
Authors
- Nan Zhao (ORCID: https://orcid.org/0000-0002-0816-1891)
- Tao Xie (ORCID: https://orcid.org/0000-0002-1506-802X)
- Stanislav M. Avdoshenko (ORCID: https://orcid.org/0000-0001-5839-3079)
- A. Podlesnyak (ORCID: https://orcid.org/0000-0001-9366-6319)
- Athena S. Sefat (ORCID: https://orcid.org/0000-0002-5596-3504)
- Andreas M. Läuchli (ORCID: https://orcid.org/0000-0002-2272-2691)
- С. Е. Никитин (ORCID: https://orcid.org/0000-0001-8495-1038)
- Jie Xing (ORCID: https://orcid.org/0000-0002-9732-2318)
- A. L. Chernyshev (ORCID: https://orcid.org/0000-0003-0965-568X)
- Samuel Gozel (ORCID: https://orcid.org/0000-0003-4759-4881)
- Liusuo Wu (ORCID: https://orcid.org/0000-0003-0103-5267)
Institutions
- Oak Ridge National Laboratory (US)
- Sun Yat-sen University (CN)
- University of California, Irvine (US)
- Paul Scherrer Institute (CH)
- University of California System (US)
- Leibniz Institute for Solid State and Materials Research (DE)
- Southern University of Science and Technology (CN)
- École Polytechnique Fédérale de Lausanne (CH)
Publication Details
- Journal
- Physical Review Letters
- Published
- 2024-08-29
- DOI
- https://doi.org/10.1103/physrevlett.133.096703
- Citations
- 16
- Primary Topic
- Advanced Condensed Matter Physics
- Type
- article
- Field-Weighted Citation Impact
- 4.97
Funders
- U.S. Department of Energy
- National Natural Science Foundation of China
- Sun Yat-sen University
- Office of Science
- Fundamental Research Funds for the Central Universities
- Basic Energy Sciences
- Oak Ridge National Laboratory
- Division of Materials Sciences and Engineering