Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice
Abstract
Currently under active study in condensed matter physics, both theoretically and experimentally, are quantum spin liquid (QSL) states, in which no long-range magnetic ordering appears at low temperatures due to strong quantum fluctuations of the magnetic moments. The existing QSL candidates all have their intrinsic disadvantages, however, and solid evidence for quantum fluctuations is scarce. Here, we report a previously unreported compound, Na2BaCo(PO4)2, a geometrically frustrated system with effective spin-1/2 local moments for Co2+ ions on an isotropic 2-dimensional (2D) triangular lattice. Magnetic susceptibility and neutron scattering experiments show no magnetic ordering down to 0.05 K. Thermodynamic measurements show that there is a tremendous amount of magnetic entropy present below 1 K in 0-applied magnetic field. The presence of localized low-energy spin fluctuations is revealed by inelastic neutron measurements. At low applied fields, these spin excitations are confined to low energy and contribute to the anomalously large specific heat. In larger applied fields, the system reverts to normal behavior as evident by both neutron and thermodynamic results. Our experimental characterization thus reveals that this material is an excellent candidate for the experimental realization of a QSL state.
- Authors:
- Publication Date:
- Research Org.:
- Energy Frontier Research Centers (EFRC) (United States). Institute for Quantum Matter (IQM); Johns Hopkins Univ., Baltimore, MD (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC); National Institute of Standards and Technology; US Department of Commerce; Gordon and Betty Moore Emergent Phenomena in Quantum System (EPiQS) Program
- OSTI Identifier:
- 1564522
- Alternate Identifier(s):
- OSTI ID: 1613182; OSTI ID: 1825715
- Grant/Contract Number:
- SC0019331; GBMF-4412
- Resource Type:
- Published Article
- Journal Name:
- Proceedings of the National Academy of Sciences of the United States of America
- Additional Journal Information:
- Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Volume: 116 Journal Issue: 29; Journal ID: ISSN 0027-8424
- Publisher:
- National Academy of Sciences
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; science & technology - other topics; quantum spin liquids; geometric frustrated magnets; quantum fluctuation; triangular lattice
Citation Formats
Zhong, Ruidan, Guo, Shu, Xu, Guangyong, Xu, Zhijun, and Cava, Robert J. Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice. United States: N. p., 2019.
Web. doi:10.1073/pnas.1906483116.
Zhong, Ruidan, Guo, Shu, Xu, Guangyong, Xu, Zhijun, & Cava, Robert J. Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice. United States. https://doi.org/10.1073/pnas.1906483116
Zhong, Ruidan, Guo, Shu, Xu, Guangyong, Xu, Zhijun, and Cava, Robert J. Tue .
"Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice". United States. https://doi.org/10.1073/pnas.1906483116.
@article{osti_1564522,
title = {Strong quantum fluctuations in a quantum spin liquid candidate with a Co-based triangular lattice},
author = {Zhong, Ruidan and Guo, Shu and Xu, Guangyong and Xu, Zhijun and Cava, Robert J.},
abstractNote = {Currently under active study in condensed matter physics, both theoretically and experimentally, are quantum spin liquid (QSL) states, in which no long-range magnetic ordering appears at low temperatures due to strong quantum fluctuations of the magnetic moments. The existing QSL candidates all have their intrinsic disadvantages, however, and solid evidence for quantum fluctuations is scarce. Here, we report a previously unreported compound, Na2BaCo(PO4)2, a geometrically frustrated system with effective spin-1/2 local moments for Co2+ ions on an isotropic 2-dimensional (2D) triangular lattice. Magnetic susceptibility and neutron scattering experiments show no magnetic ordering down to 0.05 K. Thermodynamic measurements show that there is a tremendous amount of magnetic entropy present below 1 K in 0-applied magnetic field. The presence of localized low-energy spin fluctuations is revealed by inelastic neutron measurements. At low applied fields, these spin excitations are confined to low energy and contribute to the anomalously large specific heat. In larger applied fields, the system reverts to normal behavior as evident by both neutron and thermodynamic results. Our experimental characterization thus reveals that this material is an excellent candidate for the experimental realization of a QSL state.},
doi = {10.1073/pnas.1906483116},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
number = 29,
volume = 116,
place = {United States},
year = {2019},
month = {7}
}
https://doi.org/10.1073/pnas.1906483116
Web of Science
Figures / Tables:

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