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arXiv · 2405.17385

Thermalization and Criticality on an Analog-Digital Quantum Simulator

Trond I. Andersen·Nikita Astrakhantsev·Amir H. Karamlou·Julia Berndtsson·Johannes Motruk·Aaron Szasz·Jonathan A. Gross·Alexander Schuckert·Tom Westerhout·Yaxing Zhang·Ebrahim Forati·Dario Rossi·Bryce Kobrin·Agustin Di Paolo·Andrey R. Klots·Ilya Drozdov·Vladislav D. Kurilovich·Andre Petukhov·Lev B. Ioffe·Andreas Elben·Aniket Rath·Vittorio Vitale·Benoit Vermersch·Rajeev Acharya·Laleh Aghababaie Beni·Kyle Anderson·Markus Ansmann·Frank Arute·Kunal Arya·Abraham Asfaw·Juan Atalaya·Brian Ballard·Joseph C. Bardin·Andreas Bengtsson·Alexander Bilmes·Gina Bortoli·Alexandre Bourassa·Jenna Bovaird·Leon Brill·Michael Broughton·David A. Browne·Brett Buchea·Bob B. Buckley·David A. Buell·Tim Burger·Brian Burkett·Nicholas Bushnell·Anthony Cabrera·Juan Campero·Hung-Shen Chang·Zijun Chen·Ben Chiaro·Jahan Claes·Agnetta Y. Cleland·Josh Cogan·Roberto Collins·Paul Conner·William Courtney·Alexander L. Crook·Sayan Das·Dripto M. Debroy·Laura De Lorenzo·Alexander Del Toro Barba·Sean Demura·Paul Donohoe·Andrew Dunsworth·Clint Earle·Alec Eickbusch·Aviv Moshe Elbag·Mahmoud Elzouka·Catherine Erickson·Lara Faoro·Reza Fatemi·Vinicius S. Ferreira·Leslie Flores Burgos·Austin G. Fowler·Brooks Foxen·Suhas Ganjam·Robert Gasca·William Giang·Craig Gidney·Dar Gilboa·Marissa Giustina·Raja Gosula·Alejandro Grajales Dau·Dietrich Graumann·Alex Greene·Steve Habegger·Michael C. Hamilton·Monica Hansen·Matthew P. Harrigan·Sean D. Harrington·Stephen Heslin·Paula Heu·Gordon Hill·Markus R. Hoffmann·Hsin-Yuan Huang·Trent Huang·Ashley Huff·William J. Huggins
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Abstract

Understanding how interacting particles approach thermal equilibrium is a major challenge of quantum simulators. Unlocking the full potential of such systems toward this goal requires flexible initial state preparation, precise time evolution, and extensive probes for final state characterization. We present a quantum simulator comprising 69 superconducting qubits which supports both universal quantum gates and high-fidelity analog evolution, with performance beyond the reach of classical simulation in cross-entropy benchmarking experiments. Emulating a two-dimensional (2D) XY quantum magnet, we leverage a wide range of measurement techniques to study quantum states after ramps from an antiferromagnetic initial state. We observe signatures of the classical Kosterlitz-Thouless phase transition, as well as strong deviations from Kibble-Zurek scaling predictions attributed to the interplay between quantum and classical coarsening of the correlated domains. This interpretation is corroborated by injecting variable energy density into the initial state, which enables studying the effects of the eigenstate thermalization hypothesis (ETH) in targeted parts of the eigenspectrum. Finally, we digitally prepare the system in pairwise-entangled dimer states and image the transport of energy and vorticity during thermalization. These results establish the efficacy of superconducting analog-digital quantum processors for preparing states across many-body spectra and unveiling their thermalization dynamics.

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Trond I. Andersen, Nikita Astrakhantsev, Amir H. Karamlou, Julia Berndtsson, Johannes Motruk, Aaron Szasz, Jonathan A. Gross, Alexander Schuckert, Tom Westerhout, Yaxing Zhang, Ebrahim Forati, Dario Rossi, Bryce Kobrin, Agustin Di Paolo, Andrey R. Klots, Ilya Drozdov, Vladislav D. Kurilovich, Andre Petukhov, Lev B. Ioffe, Andreas Elben, Aniket Rath, Vittorio Vitale, Benoit Vermersch, Rajeev Acharya, Laleh Aghababaie Beni, Kyle Anderson, Markus Ansmann, Frank Arute, Kunal Arya, Abraham Asfaw, Juan Atalaya, Brian Ballard, Joseph C. Bardin, Andreas Bengtsson, Alexander Bilmes, Gina Bortoli, Alexandre Bourassa, Jenna Bovaird, Leon Brill, Michael Broughton, David A. Browne, Brett Buchea, Bob B. Buckley, David A. Buell, Tim Burger, Brian Burkett, Nicholas Bushnell, Anthony Cabrera, Juan Campero, Hung-Shen Chang, Zijun Chen, Ben Chiaro, Jahan Claes, Agnetta Y. Cleland, Josh Cogan, Roberto Collins, Paul Conner, William Courtney, Alexander L. Crook, Sayan Das, Dripto M. Debroy, Laura De Lorenzo, Alexander Del Toro Barba, Sean Demura, Paul Donohoe, Andrew Dunsworth, Clint Earle, Alec Eickbusch, Aviv Moshe Elbag, Mahmoud Elzouka, Catherine Erickson, Lara Faoro, Reza Fatemi, Vinicius S. Ferreira, Leslie Flores Burgos, Austin G. Fowler, Brooks Foxen, Suhas Ganjam, Robert Gasca, William Giang, Craig Gidney, Dar Gilboa, Marissa Giustina, Raja Gosula, Alejandro Grajales Dau, Dietrich Graumann, Alex Greene, Steve Habegger, Michael C. Hamilton, Monica Hansen, Matthew P. Harrigan, Sean D. Harrington, Stephen Heslin, Paula Heu, Gordon Hill, Markus R. Hoffmann, Hsin-Yuan Huang, Trent Huang, Ashley Huff, William J. Huggins. 2024-05-27. Thermalization and Criticality on an Analog-Digital Quantum Simulator. https://arxiv.org/abs/2405.17385

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