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arXiv · 2107.13571

Observation of Time-Crystalline Eigenstate Order on a Quantum Processor

Xiao Mi·Matteo Ippoliti·Chris Quintana·Ami Greene·Zijun Chen·Jonathan Gross·Frank Arute·Kunal Arya·Juan Atalaya·Ryan Babbush·Joseph C. Bardin·Joao Basso·Andreas Bengtsson·Alexander Bilmes·Alexandre Bourassa·Leon Brill·Michael Broughton·Bob B. Buckley·David A. Buell·Brian Burkett·Nicholas Bushnell·Benjamin Chiaro·Roberto Collins·William Courtney·Dripto Debroy·Sean Demura·Alan R. Derk·Andrew Dunsworth·Daniel Eppens·Catherine Erickson·Edward Farhi·Austin G. Fowler·Brooks Foxen·Craig Gidney·Marissa Giustina·Matthew P. Harrigan·Sean D. Harrington·Jeremy Hilton·Alan Ho·Sabrina Hong·Trent Huang·Ashley Huff·William J. Huggins·L. B. Ioffe·Sergei V. Isakov·Justin Iveland·Evan Jeffrey·Zhang Jiang·Cody Jones·Dvir Kafri·Tanuj Khattar·Seon Kim·Alexei Kitaev·Paul V. Klimov·Alexander N. Korotkov·Fedor Kostritsa·David Landhuis·Pavel Laptev·Joonho Lee·Kenny Lee·Aditya Locharla·Erik Lucero·Orion Martin·Jarrod R. McClean·Trevor McCourt·Matt McEwen·Kevin C. Miao·Masoud Mohseni·Shirin Montazeri·Wojciech Mruczkiewicz·Ofer Naaman·Matthew Neeley·Charles Neill·Michael Newman·Murphy Yuezhen Niu·Thomas E. O\' Brien·Alex Opremcak·Eric Ostby·Balint Pato·Andre Petukhov·Nicholas C. Rubin·Daniel Sank·Kevin J. Satzinger·Vladimir Shvarts·Yuan Su·Doug Strain·Marco Szalay·Matthew D. Trevithick·Benjamin Villalonga·Theodore White·Z. Jamie Yao·Ping Yeh·Juhwan Yoo·Adam Zalcman·Hartmut Neven·Sergio Boixo·Vadim Smelyanskiy·Anthony Megrant·Julian Kelly·Yu Chen

Abstract

Quantum many-body systems display rich phase structure in their low-temperature equilibrium states. However, much of nature is not in thermal equilibrium. Remarkably, it was recently predicted that out-of-equilibrium systems can exhibit novel dynamical phases that may otherwise be forbidden by equilibrium thermodynamics, a paradigmatic example being the discrete time crystal (DTC). Concretely, dynamical phases can be defined in periodically driven many-body localized systems via the concept of eigenstate order. In eigenstate-ordered phases, the entire many-body spectrum exhibits quantum correlations and long-range order, with characteristic signatures in late-time dynamics from all initial states. It is, however, challenging to experimentally distinguish such stable phases from transient phenomena, wherein few select states can mask typical behavior. Here we implement a continuous family of tunable CPHASE gates on an array of superconducting qubits to experimentally observe an eigenstate-ordered DTC. We demonstrate the characteristic spatiotemporal response of a DTC for generic initial states. Our work employs a time-reversal protocol that discriminates external decoherence from intrinsic thermalization, and leverages quantum typicality to circumvent the exponential cost of densely sampling the eigenspectrum. In addition, we locate the phase transition out of the DTC with an experimental finite-size analysis. These results establish a scalable approach to study non-equilibrium phases of matter on current quantum processors.

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Xiao Mi, Matteo Ippoliti, Chris Quintana, Ami Greene, Zijun Chen, Jonathan Gross, Frank Arute, Kunal Arya, Juan Atalaya, Ryan Babbush, Joseph C. Bardin, Joao Basso, Andreas Bengtsson, Alexander Bilmes, Alexandre Bourassa, Leon Brill, Michael Broughton, Bob B. Buckley, David A. Buell, Brian Burkett, Nicholas Bushnell, Benjamin Chiaro, Roberto Collins, William Courtney, Dripto Debroy, Sean Demura, Alan R. Derk, Andrew Dunsworth, Daniel Eppens, Catherine Erickson, Edward Farhi, Austin G. Fowler, Brooks Foxen, Craig Gidney, Marissa Giustina, Matthew P. Harrigan, Sean D. Harrington, Jeremy Hilton, Alan Ho, Sabrina Hong, Trent Huang, Ashley Huff, William J. Huggins, L. B. Ioffe, Sergei V. Isakov, Justin Iveland, Evan Jeffrey, Zhang Jiang, Cody Jones, Dvir Kafri, Tanuj Khattar, Seon Kim, Alexei Kitaev, Paul V. Klimov, Alexander N. Korotkov, Fedor Kostritsa, David Landhuis, Pavel Laptev, Joonho Lee, Kenny Lee, Aditya Locharla, Erik Lucero, Orion Martin, Jarrod R. McClean, Trevor McCourt, Matt McEwen, Kevin C. Miao, Masoud Mohseni, Shirin Montazeri, Wojciech Mruczkiewicz, Ofer Naaman, Matthew Neeley, Charles Neill, Michael Newman, Murphy Yuezhen Niu, Thomas E. O\' Brien, Alex Opremcak, Eric Ostby, Balint Pato, Andre Petukhov, Nicholas C. Rubin, Daniel Sank, Kevin J. Satzinger, Vladimir Shvarts, Yuan Su, Doug Strain, Marco Szalay, Matthew D. Trevithick, Benjamin Villalonga, Theodore White, Z. Jamie Yao, Ping Yeh, Juhwan Yoo, Adam Zalcman, Hartmut Neven, Sergio Boixo, Vadim Smelyanskiy, Anthony Megrant, Julian Kelly, Yu Chen. 2021-08-11. Observation of Time-Crystalline Eigenstate Order on a Quantum Processor. https://doi.org/10.1038/s41586-021-04257-w

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