Spin liquid to spin glass crossover in the random quantum Heisenberg magnet
Spin liquid to spin glass crossover in the random quantum Heisenberg magnet
We study quantum SU(M) spins with all-to-all and random Heisenberg exchange interactions of root-mean-square strength J. The M→∞ model has a quantum spin liquid ground state with the spinons obeying the equations of the Sachdev-Ye-Kitaev (SYK) model. Numerical studies of the SU(2) model with S=1/2 spins show spin glass order in the ground state, but also display SYK spin liquid behavior in the intermediate frequency spin spectrum. We employ a 1/M expansion to describe the crossover from fractionalized fermionic spinons to a confining spin glass state with weak spin glass order qEA. The SYK spin liquid behavior persists down to a frequency ω∗∼JqEA, and for ω<ω∗, the spin spectral density is linear in ω, thus quenching the extensive zero temperature entropy of the spin liquid. The linear ω spectrum is qualitatively similar to that obtained earlier using bosonic spinons for large qEA. We argue that the extensive SYK spin liquid entropy is transformed as T→0 to an extensive complexity of the spin glass state. We comment on holographic connections of the confinement transition to the fragmentation of black holes with AdS2 horizons.
Christos, Maine
b65c0b30-6232-49d0-8beb-65598e597555
Haehl, Felix M.
eb0d74fd-0d8b-4b1b-8686-79d43c2a3a5f
Sachdev, Subir
60a3d82c-2a68-49a7-b047-4795beb27e03
14 February 2022
Christos, Maine
b65c0b30-6232-49d0-8beb-65598e597555
Haehl, Felix M.
eb0d74fd-0d8b-4b1b-8686-79d43c2a3a5f
Sachdev, Subir
60a3d82c-2a68-49a7-b047-4795beb27e03
Christos, Maine, Haehl, Felix M. and Sachdev, Subir
(2022)
Spin liquid to spin glass crossover in the random quantum Heisenberg magnet.
Physical Review B, 105 (8), [085120].
(doi:10.1103/PhysRevB.105.085120).
Abstract
We study quantum SU(M) spins with all-to-all and random Heisenberg exchange interactions of root-mean-square strength J. The M→∞ model has a quantum spin liquid ground state with the spinons obeying the equations of the Sachdev-Ye-Kitaev (SYK) model. Numerical studies of the SU(2) model with S=1/2 spins show spin glass order in the ground state, but also display SYK spin liquid behavior in the intermediate frequency spin spectrum. We employ a 1/M expansion to describe the crossover from fractionalized fermionic spinons to a confining spin glass state with weak spin glass order qEA. The SYK spin liquid behavior persists down to a frequency ω∗∼JqEA, and for ω<ω∗, the spin spectral density is linear in ω, thus quenching the extensive zero temperature entropy of the spin liquid. The linear ω spectrum is qualitatively similar to that obtained earlier using bosonic spinons for large qEA. We argue that the extensive SYK spin liquid entropy is transformed as T→0 to an extensive complexity of the spin glass state. We comment on holographic connections of the confinement transition to the fragmentation of black holes with AdS2 horizons.
Text
2110.00007v1
- Author's Original
More information
Submitted date: 18 October 2021
Accepted/In Press date: 26 January 2022
Published date: 14 February 2022
Additional Information:
Funding Information:
We thank Tom Banks, Debanjan Chowdhury, Antoine Georges, Darshan Joshi, Chenyuan Li, Juan Maldacena, Olivier Parcollet, Henry Shackleton, Grigory Tarnopolsky, Maria Tikhanovskaya, and Alexander Wietek for helpful discussions. This research was supported by the National Science Foundation under Grant No. DMR-2002850. This work was also supported by the Simons Collaboration on Ultra-Quantum Matter, which is a grant from the Simons Foundation (651440, S.S.). F.H. is supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC0009988, and by the Paul Dirac and Sivian Funds.
Publisher Copyright:
© 2022 American Physical Society.
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Local EPrints ID: 470067
URI: http://eprints.soton.ac.uk/id/eprint/470067
ISSN: 1550-235X
PURE UUID: 61c3b879-4eb1-4bd1-ac14-b7b1f06935bf
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Date deposited: 03 Oct 2022 16:31
Last modified: 17 Mar 2024 04:14
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Author:
Maine Christos
Author:
Felix M. Haehl
Author:
Subir Sachdev
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