Scrambling and thermalization in a diffusive quantum many-body system

By Annabelle Bohrdt, Christian B. Mendl, M. Endres, Michael Jason Knap. 2016

242 citations recorded by the source corpus.

Out-of-time ordered (OTO) correlation functions describe scrambling of information in correlated quantum matter. They are of particular interest in incoherent quantum systems lacking well defined quasi-particles. Thus far, it is largely elusive how OTO correlators spread in incoherent systems with diffusive transport governed by a few globally conserved quantities. Here, we study the dynamical response of such a system using high-performance matrix-product-operator techniques. Specifically, we consider the non-integrable, one-dimensional Bose–Hubbard model in the incoherent high-temperature regime. Our system exhibits diffusive dynamics in time-ordered correlators of globally conserved quantities, whereas OTO correlators display a ballistic, light-cone spreading of quantum information. The slowest process in the global thermalization of the system is thus diffusive, yet information spreading is not inhibited by such slow dynamics. We furthermore develop an experimentally feasible protocol to overcome some challenges faced by existing proposals and to probe time-ordered and OTO correlation functions. Our study opens new avenues for both the theoretical and experimental exploration of thermalization and information scrambling dynamics.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/e5ee81ea5e12ff51fa9ad1a94603d318d1d4e6e5

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In Atomic and Molecular Physics, and Optics

Citations in the corpus

Diffusive Hydrodynamics of Out-of-Time-Ordered Correlators with Charge Conservation (2017, methodology): “In more generic systems, however, not much is known about the detailed dependence of outof-time-ordered correlators on temperature [22].”
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Scrambling Dynamics and Out-of-Time-Ordered Correlators in Quantum Many-Body Systems (2022, background): “For a generic system with short-ranged interaction and no disorder, local operators spread ballistically, which has been shown in numerous systems including field theories [54, 55], free and integrable models [56, 57], interacting spin chains [58, 59] and circuit models [60–63].”
Emergent statistical mechanics of entanglement in random unitary circuits (2018, unknown): “[38] A Bohrdt, CB Mendl, M Endres, and M Knap.”
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