Quantum Butterfly Effect in Weakly Interacting Diffusive Metals

We study scrambling, an avatar of chaos, in a weakly interacting metal in the presence of random potential disorder. It is well known that charge and heat spread via diffusion in such an interacting disordered metal. In contrast, we show within perturbation theory that chaos spreads in a ballistic f...

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Main Authors: Patel, Aavishkar A., Sachdev, Subir, Chowdhury, Debanjan, Swingle, Brian Gordon
Other Authors: Massachusetts Institute of Technology. Department of Physics
Format: Article
Published: American Physical Society 2018
Online Access:http://hdl.handle.net/1721.1/114255
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author Patel, Aavishkar A.
Sachdev, Subir
Chowdhury, Debanjan
Swingle, Brian Gordon
author2 Massachusetts Institute of Technology. Department of Physics
author_facet Massachusetts Institute of Technology. Department of Physics
Patel, Aavishkar A.
Sachdev, Subir
Chowdhury, Debanjan
Swingle, Brian Gordon
author_sort Patel, Aavishkar A.
collection MIT
description We study scrambling, an avatar of chaos, in a weakly interacting metal in the presence of random potential disorder. It is well known that charge and heat spread via diffusion in such an interacting disordered metal. In contrast, we show within perturbation theory that chaos spreads in a ballistic fashion. The squared anticommutator of the electron-field operators inherits a light-cone-like growth, arising from an interplay of a growth (Lyapunov) exponent that scales as the inelastic electron scattering rate and a diffusive piece due to the presence of disorder. In two spatial dimensions, the Lyapunov exponent is universally related at weak coupling to the sheet resistivity. We are able to define an effective temperature-dependent butterfly velocity, a speed limit for the propagation of quantum information that is much slower than microscopic velocities such as the Fermi velocity and that is qualitatively similar to that of a quantum critical system with a dynamical critical exponent z > 1.
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spelling mit-1721.1/1142552022-10-01T23:16:03Z Quantum Butterfly Effect in Weakly Interacting Diffusive Metals Patel, Aavishkar A. Sachdev, Subir Chowdhury, Debanjan Swingle, Brian Gordon Massachusetts Institute of Technology. Department of Physics Chowdhury, Debanjan Swingle, Brian Gordon We study scrambling, an avatar of chaos, in a weakly interacting metal in the presence of random potential disorder. It is well known that charge and heat spread via diffusion in such an interacting disordered metal. In contrast, we show within perturbation theory that chaos spreads in a ballistic fashion. The squared anticommutator of the electron-field operators inherits a light-cone-like growth, arising from an interplay of a growth (Lyapunov) exponent that scales as the inelastic electron scattering rate and a diffusive piece due to the presence of disorder. In two spatial dimensions, the Lyapunov exponent is universally related at weak coupling to the sheet resistivity. We are able to define an effective temperature-dependent butterfly velocity, a speed limit for the propagation of quantum information that is much slower than microscopic velocities such as the Fermi velocity and that is qualitatively similar to that of a quantum critical system with a dynamical critical exponent z > 1. United States. Army Research Office (Grant W911NF-14-1-0003) 2018-03-21T19:10:00Z 2018-03-21T19:10:00Z 2017-09 2017-05 2018-03-02T14:33:50Z Article http://purl.org/eprint/type/JournalArticle 2160-3308 http://hdl.handle.net/1721.1/114255 Patel, Aavishkar A. et al. “Quantum Butterfly Effect in Weakly Interacting Diffusive Metals.” Physical Review X 7, 3 (September 2017): 031047 © The Author(s) http://dx.doi.org/10.1103/PhysRevX.7.031047 Physical Review X Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/ application/pdf American Physical Society Physical Review X
spellingShingle Patel, Aavishkar A.
Sachdev, Subir
Chowdhury, Debanjan
Swingle, Brian Gordon
Quantum Butterfly Effect in Weakly Interacting Diffusive Metals
title Quantum Butterfly Effect in Weakly Interacting Diffusive Metals
title_full Quantum Butterfly Effect in Weakly Interacting Diffusive Metals
title_fullStr Quantum Butterfly Effect in Weakly Interacting Diffusive Metals
title_full_unstemmed Quantum Butterfly Effect in Weakly Interacting Diffusive Metals
title_short Quantum Butterfly Effect in Weakly Interacting Diffusive Metals
title_sort quantum butterfly effect in weakly interacting diffusive metals
url http://hdl.handle.net/1721.1/114255
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