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Information scrambling in quantum circuits

Mi, Xiao and Roushan, Pedram and Quintana, Chris and Mandrà, Salvatore and Marshall, Jeffrey and Neill, Charles and Arute, Frank and Arya, Kunal and Atalaya, Juan and Babbush, Ryan and Bardin, Joseph C. and Barends, Rami and Basso, Joao and Bengtsson, Andreas and Boixo, Sergio and Bourassa, Alexandre and Broughton, Michael and Buckley, Bob B. and Buell, David A. and Burkett, Brian and Bushnell, Nicholas and Chen, Zijun and Chiaro, Benjamin and Collins, Roberto and Courtney, William and Demura, Sean and Derk, Alan R. and Dunsworth, Andrew and Eppens, Daniel and Erickson, Catherine and Farhi, Edward and Fowler, Austin G. and Foxen, Brooks and Gidney, Craig and Giustina, Marissa and Gross, Jonathan A. and Harrigan, Matthew P. and Harrington, Sean D. and Hilton, Jeremy and Ho, Alan and Hong, Sabrina and Huang, Trent and Huggins, William J. and Ioffe, L. B. and Isakov, Sergei V. and Jeffrey, Evan and Jiang, Zhang and Jones, Cody and Kafri, Dvir and Kelly, Julian and Kim, Seon and Kitaev, Alexei and Klimov, Paul V. and Korotkov, Alexander N. and Kostritsa, Fedor and Landhuis, David and Laptev, Pavel and Lucero, Erik and Martin, Orion and McClean, Jarrod R. and McCourt, Trevor and McEwen, Matt and Megrant, Anthony and Miao, Kevin C. and Mohseni, Masoud and Montazeri, Shirin and Mruczkiewicz, Wojciech and Mutus, Josh and Naaman, Ofer and Neeley, Matthew and Newman, Michael and Niu, Murphy Yuezhen and O'Brien, Thomas E. and Opremcak, Alex and Ostby, Eric and Pato, Balint and Petukhov, Andre and Redd, Nicholas and Rubin, Nicholas C. and Sank, Daniel and Satzinger, Kevin J. and Shvarts, Vladimir and Strain, Doug and Szalay, Marco and Trevithick, Matthew D. and Villalonga, Benjamin and White, Theodore and Yao, Z. Jamie and Yeh, Ping and Zalcman, Adam and Neven, Hartmut and Aleiner, Igor and Kechedzhi, Kostyantyn and Smelyanskiy, Vadim and Chen, Yu (2021) Information scrambling in quantum circuits. Science, 374 (6574). pp. 1479-1483. ISSN 0036-8075. doi:10.1126/science.abg5029.

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Interactions in quantum systems can spread initially localized quantum information into the exponentially many degrees of freedom of the entire system. Understanding this process, known as quantum scrambling, is key to resolving several open questions in physics. Here, by measuring the time-dependent evolution and fluctuation of out-of-time-order correlators, we experimentally investigate the dynamics of quantum scrambling on a 53-qubit quantum processor. We engineer quantum circuits that distinguish operator spreading and operator entanglement and experimentally observe their respective signatures. We show that whereas operator spreading is captured by an efficient classical model, operator entanglement in idealized circuits requires exponentially scaled computational resources to simulate. These results open the path to studying complex and practically relevant physical observables with near-term quantum processors.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Mi, Xiao0000-0003-0507-0211
Roushan, Pedram0000-0003-1917-3879
Quintana, Chris0000-0003-4408-8318
Mandrà, Salvatore0000-0002-3908-2694
Marshall, Jeffrey0000-0002-5011-1281
Neill, Charles0000-0002-6563-3568
Arya, Kunal0000-0002-6486-7100
Atalaya, Juan0000-0003-3055-2730
Babbush, Ryan0000-0001-6979-9533
Bardin, Joseph C.0000-0002-6523-6730
Basso, Joao0000-0001-5547-691X
Bengtsson, Andreas0000-0001-5264-4025
Boixo, Sergio0000-0002-1090-7584
Bourassa, Alexandre0000-0002-8517-7475
Buckley, Bob B.0000-0001-5139-7931
Burkett, Brian0000-0001-8474-6317
Bushnell, Nicholas0000-0001-7445-1654
Chiaro, Benjamin0000-0002-2913-2790
Collins, Roberto0000-0002-6164-0007
Demura, Sean0000-0003-3727-7380
Eppens, Daniel0000-0001-7134-5733
Fowler, Austin G.0000-0002-9048-2896
Foxen, Brooks0000-0002-3732-168X
Gross, Jonathan A.0000-0001-7049-6206
Harrigan, Matthew P.0000-0001-9412-0553
Harrington, Sean D.0000-0003-0521-8378
Huggins, William J.0000-0003-2735-1380
Ioffe, L. B.0000-0002-8777-6789
Jiang, Zhang0000-0003-0435-655X
Kafri, Dvir0000-0001-9160-5176
Kelly, Julian0000-0002-2596-2121
Kim, Seon0000-0003-3397-0444
Kitaev, Alexei0000-0002-5777-642X
Landhuis, David0000-0001-9804-2185
Lucero, Erik0000-0002-6449-2273
Martin, Orion0000-0002-9576-573X
McClean, Jarrod R.0000-0002-2809-0509
McEwen, Matt0000-0002-9544-141X
Megrant, Anthony0000-0002-6371-6140
Mruczkiewicz, Wojciech0000-0002-8497-6363
Naaman, Ofer0000-0002-7760-9186
Neeley, Matthew0000-0002-5548-0051
O'Brien, Thomas E.0000-0002-8406-6626
Redd, Nicholas0000-0002-6549-5441
Rubin, Nicholas C.0000-0003-3963-1830
Sank, Daniel0000-0001-8188-364X
Satzinger, Kevin J.0000-0001-5865-0813
Szalay, Marco0000-0002-1310-9174
Trevithick, Matthew D.0000-0001-6700-3140
White, Theodore0000-0002-9803-7471
Yao, Z. Jamie0000-0003-1806-5454
Yeh, Ping0000-0003-0837-1028
Zalcman, Adam0000-0002-2585-2424
Neven, Hartmut0000-0002-9681-6746
Kechedzhi, Kostyantyn0000-0002-0136-1428
Smelyanskiy, Vadim0000-0002-3000-6732
Chen, Yu0000-0002-7473-6745
Additional Information:© 2021 American Association for the Advancement of Science. Received 9 January 2021; accepted 19 October 2021. Published online 28 October 2021. P.R. and X.M. acknowledge fruitful discussions with P. Zoller, B. Vermersch, A. Elben, and M. Knapp. S.Ma. and J.Ma. acknowledge support from the NASA Ames Research Center and support from the NASA Advanced Supercomputing Division for providing access to the NASA HPC systems, Pleiades and Merope. S.Ma. and J.Ma. also acknowledge support from the AFRL Information Directorate under grant no. F4HBKC4162G001. J.Ma. is partially supported by NAMS contract no. NNA16BD14C. S.Ma. is also supported by the Prime contract no. 80ARC020D0010 with the NASA Ames Research Center. Author contributions: V.Sm., K.K., X.M., and P.R. devised the experiment. X.M., C.Q., and P.R. executed the experiment on the Google quantum hardware. X.M., P.R., K.K., and Y.C. wrote the manuscript. X.M., S.Ma., J.Ma., and K.K. wrote the supplementary materials. V.Sm., I.A., X.M., K.K., S.Ma., and J.Ma. provided theoretical support, analysis techniques, and numerical computations. I.A. and K.K. developed the Markov process model. S.Ma. designed and performed the large-scale numerical simulation, including the algorithms and software development. J.Ma. performed the noisy numerical simulations. P.R., Y.C., V.Sm., and H.N. led and coordinated the project. Infrastructure support was provided by the Google Quantum AI hardware team. The NASA Advanced Supercomputing Division at NASA Ames provided the infrastructure to run high-performance computing (HPC) simulations. All authors contributed to revising the manuscript and the supplementary materials. The authors declare no competing interest. Data and materials availability: All experimental and numerical data in the main text and supplementary materials, along with the software code for generating quantum circuits, measurements, population dynamics simulation, and tensor contraction simulation are available at Zenodo (43).
Group:Institute for Quantum Information and Matter
Funding AgencyGrant Number
Air Force Research Laboratory (AFRL)F4HBKC4162G001
Issue or Number:6574
Record Number:CaltechAUTHORS:20211028-210102101
Persistent URL:
Official Citation:Information scrambling in quantum circuits. Xiao Mi, et. al., Science, 374 (6574); DOI: 10.1126/science.abg5029
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:111675
Deposited By: Tony Diaz
Deposited On:28 Oct 2021 22:13
Last Modified:06 Dec 2022 18:49

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