TY - JOUR
T1 - Preparing random states and benchmarking with many-body quantum chaos
AU - Choi, Joonhee
AU - Shaw, Adam L.
AU - Madjarov, Ivaylo S.
AU - Xie, Xin
AU - Finkelstein, Ran
AU - Covey, Jacob P.
AU - Cotler, Jordan S.
AU - Mark, Daniel K.
AU - Huang, Hsin Yuan
AU - Kale, Anant
AU - Pichler, Hannes
AU - Brandão, Fernando G.S.L.
AU - Choi, Soonwon
AU - Endres, Manuel
N1 - Funding Information:
We acknowledge experimental help from P. Scholl during the revision of this manuscript, as well as discussions with A. Deshpande and A. Gorshkov. We acknowledge funding provided by the Institute for Quantum Information and Matter, an NSF Physics Frontiers Center (NSF grant no. PHY-1733907), the NSF CAREER award (no. 1753386), the AFOSR YIP (no. FA9550-19-1-0044), the DARPA ONISQ programme (no. W911NF2010021), the Army Research Office MURI program (no. W911NF2010136), the NSF QLCI program (no. 2016245), the DOE (grant no. DE-SC0021951), the US Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Systems Accelerator (grant no. DE-AC02-05CH11231) and F. Blum. J.C. acknowledges support from the IQIM postdoctoral fellowship. A.L.S. acknowledges support from the Eddleman Quantum graduate fellowship. R.F. acknowledges support from the Troesh postdoctoral fellowship. J.P.C. acknowledges support from the PMA Prize postdoctoral fellowship. H.P. acknowledges support by the Gordon and Betty Moore Foundation. H.-Y.H. is supported by the J. Yang & Family Foundation. A.K. acknowledges funding from the Harvard Quantum Initiative (HQI) graduate fellowship. J.S.C. is supported by a Junior Fellowship from the Harvard Society of Fellows and the US Department of Energy under grant contract no. DE-SC0012567. S.C. acknowledges support from the Miller Institute for Basic Research in Science.
Publisher Copyright:
© 2023, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2023/1/19
Y1 - 2023/1/19
N2 - Producing quantum states at random has become increasingly important in modern quantum science, with applications being both theoretical and practical. In particular, ensembles of such randomly distributed, but pure, quantum states underlie our understanding of complexity in quantum circuits1 and black holes2, and have been used for benchmarking quantum devices3,4 in tests of quantum advantage5,6. However, creating random ensembles has necessitated a high degree of spatio-temporal control7–12 placing such studies out of reach for a wide class of quantum systems. Here we solve this problem by predicting and experimentally observing the emergence of random state ensembles naturally under time-independent Hamiltonian dynamics, which we use to implement an efficient, widely applicable benchmarking protocol. The observed random ensembles emerge from projective measurements and are intimately linked to universal correlations built up between subsystems of a larger quantum system, offering new insights into quantum thermalization13. Predicated on this discovery, we develop a fidelity estimation scheme, which we demonstrate for a Rydberg quantum simulator with up to 25 atoms using fewer than 104 experimental samples. This method has broad applicability, as we demonstrate for Hamiltonian parameter estimation, target-state generation benchmarking, and comparison of analogue and digital quantum devices. Our work has implications for understanding randomness in quantum dynamics14 and enables applications of this concept in a much wider context4,5,9,10,15–20.
AB - Producing quantum states at random has become increasingly important in modern quantum science, with applications being both theoretical and practical. In particular, ensembles of such randomly distributed, but pure, quantum states underlie our understanding of complexity in quantum circuits1 and black holes2, and have been used for benchmarking quantum devices3,4 in tests of quantum advantage5,6. However, creating random ensembles has necessitated a high degree of spatio-temporal control7–12 placing such studies out of reach for a wide class of quantum systems. Here we solve this problem by predicting and experimentally observing the emergence of random state ensembles naturally under time-independent Hamiltonian dynamics, which we use to implement an efficient, widely applicable benchmarking protocol. The observed random ensembles emerge from projective measurements and are intimately linked to universal correlations built up between subsystems of a larger quantum system, offering new insights into quantum thermalization13. Predicated on this discovery, we develop a fidelity estimation scheme, which we demonstrate for a Rydberg quantum simulator with up to 25 atoms using fewer than 104 experimental samples. This method has broad applicability, as we demonstrate for Hamiltonian parameter estimation, target-state generation benchmarking, and comparison of analogue and digital quantum devices. Our work has implications for understanding randomness in quantum dynamics14 and enables applications of this concept in a much wider context4,5,9,10,15–20.
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U2 - 10.1038/s41586-022-05442-1
DO - 10.1038/s41586-022-05442-1
M3 - Article
C2 - 36653567
AN - SCOPUS:85146485500
SN - 0028-0836
VL - 613
SP - 468
EP - 473
JO - Nature
JF - Nature
IS - 7944
ER -