Thermalization and possible signatures of quantum chaos in complex crystalline materials

Journal Article · 12 September 2019 · Proceedings of the National Academy of Sciences of the United States of America

DOI: https://doi.org/10.1073/pnas.1910131116 · OSTI ID:1561414

Zhang, Jiecheng  ^[1]; Kountz, Erik D. ^[1]; Behnia, Kamran ^[2]; Kapitulnik, Aharon ^[3]

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1. Department of Physics, Stanford University, Stanford, CA 94305,, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305,
2. Laboratoire Physique et Etude de Matériaux (CNRS-Sorbonne Université), École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris, Université Paris Sciences et Lettres Research University, 75005 Paris, France,
3. Department of Physics, Stanford University, Stanford, CA 94305,, Geballe Laboratory for Advanced Materials, Stanford University, Stanford, CA 94305,, Department of Applied Physics, Stanford University, Stanford, CA 94305

Significance Quantum chaos has been suggested as a framework to understand transport of charge excitations in strongly correlated electron systems exhibiting the “strange metal” state without long-lived quasiparticle excitations. Identifying a characteristic local scrambling time and a velocity by which perturbation propagates into nonlocal degrees of freedom, a chaos diffusivity is identified and related to the measured charge and energy diffusivities. Here we scrutinize the underlying hypothesis that lattice dynamics can be ignored, particularly at high temperatures, where many phonon bands and their interactions dominate the thermal transport in complex materials. We argue that much of the chaotic behavior, which is also identified in complex insulators, originates from phonons, and in equivalent itinerant systems only the thermal (energy) diffusivity describes chaos diffusivity.

• Research Organization: Stanford University, CA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1561414
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 40 Vol. 116; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of SciencesCopyright Statement
• Country of Publication: United States
• Language: English