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Emergent Randomness and Benchmarking from Many-Body Quantum Chaos

Choi, Joonhee and Shaw, Adam L. and Madjarov, Ivaylo S. and Xie, Xin and Covey, Jacob P. and Cotler, Jordan S. and Mark, Daniel K. and Huang, Hsin-Yuan and Kale, Anant and Pichler, Hannes and Brandão, Fernando G. S. L. and Choi, Soonwon and Endres, Manuel (2021) Emergent Randomness and Benchmarking from Many-Body Quantum Chaos. . (Unpublished)

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Chaotic quantum many-body dynamics typically lead to relaxation of local observables. In this process, known as quantum thermalization, a subregion reaches a thermal state due to quantum correlations with the remainder of the system, which acts as an intrinsic bath. While the bath is generally assumed to be unobserved, modern quantum science experiments have the ability to track both subsystem and bath at a microscopic level. Here, by utilizing this ability, we discover that measurement results associated with small subsystems exhibit universal random statistics following chaotic quantum many-body dynamics, a phenomenon beyond the standard paradigm of quantum thermalization. We explain these observations with an ensemble of pure states, defined via correlations with the bath, that dynamically acquires a close to random distribution. Such random ensembles play an important role in quantum information science, associated with quantum supremacy tests and device verification, but typically require highly-engineered, time-dependent control for their preparation. In contrast, our approach uncovers random ensembles naturally emerging from evolution with a time-independent Hamiltonian. As an application of this emergent randomness, we develop a benchmarking protocol which estimates the many-body fidelity during generic chaotic evolution and demonstrate it using our Rydberg quantum simulator. Our work has wide ranging implications for the understanding of quantum many-body chaos and thermalization in terms of emergent randomness and at the same time paves the way for applications of this concept in a much wider context.

Item Type:Report or Paper (Discussion Paper)
Related URLs:
URLURL TypeDescription Paper
Shaw, Adam L.0000-0002-8059-5950
Xie, Xin0000-0003-4575-6103
Covey, Jacob P.0000-0001-5104-6883
Mark, Daniel K.0000-0002-5017-5218
Huang, Hsin-Yuan0000-0001-5317-2613
Kale, Anant0000-0002-7049-5630
Pichler, Hannes0000-0003-2144-536X
Brandão, Fernando G. S. L.0000-0003-3866-9378
Choi, Soonwon0000-0002-1247-062X
Endres, Manuel0000-0002-4461-224X
Additional Information:We acknowledge discussions with Abhinav Deshpande and Alexey Gorshkov as well as funding provided by the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center (NSF Grant PHY-1733907), the NSF CAREER award (1753386), the AFOSR YIP (FA9550-19-1-0044), the DARPA ONISQ program (W911NF2010021), the Army Research Office MURI program (W911NF2010136), the NSF QLCI program (2016245), and Fred Blum. JC acknowledges support from the IQIM postdoctoral fellowship. ALS acknowledges support from the Eddleman Quantum graduate fellowship. JPC acknowledges support from the PMA Prize postdoctoral fellowship. HP acknowledges support by the Gordon and Betty Moore Foundation. HH is supported by the J. Yang & Family Foundation. AK acknowledges funding from the Harvard Quantum Initiative (HQI) graduate fellowship. JSC is supported by a Junior Fellowship from the Harvard Society of Fellows and the U.S. Department of Energy under grant Contract Number DE-SC0012567. SC acknowledges support from the Miller Institute for Basic Research in Science. JC and ALS contributed equally to this work.
Group:Institute for Quantum Information and Matter
Funding AgencyGrant Number
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
Air Force Office of Scientific Research (AFOSR)FA9550-19-1-0044
Defense Advanced Research Projects Agency (DARPA)W911NF2010021
Army Research Office (ARO)W911NF2010136
Eddleman Quantum graduate fellowshipUNSPECIFIED
Caltech Division of Physics, Mathematics and AstronomyUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
J. Yang Family and FoundationUNSPECIFIED
Harvard Quantum InitiativeUNSPECIFIED
Harvard Society of FellowsUNSPECIFIED
Department of Energy (DOE)DE-SC0012567
Miller Institute for Basic Research in ScienceUNSPECIFIED
Record Number:CaltechAUTHORS:20210512-104054951
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109101
Deposited By: George Porter
Deposited On:12 May 2021 17:58
Last Modified:12 May 2021 17:58

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