Quantum criticality among entangled spin chains
Abstract
Here, an important challenge in magnetism is the unambiguous identification of a quantum spin liquid, of potential importance for quantum computing. In such a material, the magnetic spins should be fluctuating in the quantum regime, instead of frozen in a classical longrangeordered state. While this requirement dictates systems wherein classical order is suppressed by a frustrating lattice, an ideal system would allow tuning of quantum fluctuations by an external parameter. Conventional threedimensional antiferromagnets can be tuned through a quantum critical point—a region of highly fluctuating spins—by an applied magnetic field. Such systems suffer from a weak specificheat peak at the quantum critical point, with little entropy available for quantum fluctuations. Here we study a different type of antiferromagnet, comprised of weakly coupled antiferromagnetic spin1/2 chains as realized in the molecular salt K _{2}PbCu(NO _{2}) _{6}. Across the temperature–magnetic field boundary between threedimensional order and the paramagnetic phase, the specific heat exhibits a large peak whose magnitude approaches a value suggestive of the spinon Sommerfeld coefficient of isolated quantum spin chains. These results demonstrate an alternative approach for producing quantum matter via a magneticfieldinduced shift of entropy from onedimensional shortrange order to a threedimensional quantum critical point.
 Authors:

 Univ. of California, Santa Cruz, CA (United States)
 FAMUFSU College of Engineering, Tallahassee, FL (United States); National High Magnetic Field Lab., Tallahassee, FL (United States)
 Georgia Inst. of Technology, Atlanta, GA (United States)
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Univ. of California, Santa Barbara, CA (United States)
 Publication Date:
 Research Org.:
 Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
 Sponsoring Org.:
 USDOE
 OSTI Identifier:
 1435334
 Grant/Contract Number:
 AC0500OR22725
 Resource Type:
 Accepted Manuscript
 Journal Name:
 Nature Physics
 Additional Journal Information:
 Journal Volume: 14; Journal Issue: 3; Journal ID: ISSN 17452473
 Publisher:
 Nature Publishing Group (NPG)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; Magnetic properties and materials; Phase transitions and critical phenomena; Quantum fluids and solids
Citation Formats
Blanc, N., Trinh, J., Dong, L., Bai, X., Aczel, Adam A., Mourigal, Martin P., Balents, L., Siegrist, T., and Ramirez, A. P. Quantum criticality among entangled spin chains. United States: N. p., 2017.
Web. doi:10.1038/s415670170010y.
Blanc, N., Trinh, J., Dong, L., Bai, X., Aczel, Adam A., Mourigal, Martin P., Balents, L., Siegrist, T., & Ramirez, A. P. Quantum criticality among entangled spin chains. United States. doi:10.1038/s415670170010y.
Blanc, N., Trinh, J., Dong, L., Bai, X., Aczel, Adam A., Mourigal, Martin P., Balents, L., Siegrist, T., and Ramirez, A. P. Mon .
"Quantum criticality among entangled spin chains". United States. doi:10.1038/s415670170010y. https://www.osti.gov/servlets/purl/1435334.
@article{osti_1435334,
title = {Quantum criticality among entangled spin chains},
author = {Blanc, N. and Trinh, J. and Dong, L. and Bai, X. and Aczel, Adam A. and Mourigal, Martin P. and Balents, L. and Siegrist, T. and Ramirez, A. P.},
abstractNote = {Here, an important challenge in magnetism is the unambiguous identification of a quantum spin liquid, of potential importance for quantum computing. In such a material, the magnetic spins should be fluctuating in the quantum regime, instead of frozen in a classical longrangeordered state. While this requirement dictates systems wherein classical order is suppressed by a frustrating lattice, an ideal system would allow tuning of quantum fluctuations by an external parameter. Conventional threedimensional antiferromagnets can be tuned through a quantum critical point—a region of highly fluctuating spins—by an applied magnetic field. Such systems suffer from a weak specificheat peak at the quantum critical point, with little entropy available for quantum fluctuations. Here we study a different type of antiferromagnet, comprised of weakly coupled antiferromagnetic spin1/2 chains as realized in the molecular salt K2PbCu(NO2)6. Across the temperature–magnetic field boundary between threedimensional order and the paramagnetic phase, the specific heat exhibits a large peak whose magnitude approaches a value suggestive of the spinon Sommerfeld coefficient of isolated quantum spin chains. These results demonstrate an alternative approach for producing quantum matter via a magneticfieldinduced shift of entropy from onedimensional shortrange order to a threedimensional quantum critical point.},
doi = {10.1038/s415670170010y},
journal = {Nature Physics},
number = 3,
volume = 14,
place = {United States},
year = {2017},
month = {12}
}
Web of Science
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