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arXiv:2410.06557 · Science

Observation of disorder-free localization using a (2+1)D lattice gauge theory on a quantum processor

Google AI Quantum and Collaborators, Gaurav Gyawali, Shashwat Kumar, Yuri D. Lensky, Eliott N. Rosenberg, Aaron Szasz, Tyler A. Cochran, R. Chen, Amir H. Karamlou, Noureldin Yosri, S. Meeks, Kostyantyn Kechedzhi, Julia Berndtsson, Tom Westerhout, A. Asfaw, Dmitry A. Abanin, R. Acharya, Laleh Aghababaie Beni, Trond I. Andersen, M. Ansmann, Frank Arute, Kunal Arya, N. Astrakhantsev, Juan Atalaya, Ryan Babbush, B. Ballard, Joseph C. Bardin, Andreas Bengtsson, Alexander Bilmes, Gina Bortoli, Alexandre Bourassa, Jenna Bovaird, L. BRILL, Michael Broughton, D. A. Browne, Brett Buchea, Bob B. Buckley, David A. Buell, T. Burger, Brian Burkett, Nicholas Bushnell, A. Cabrera, J. Campero, Hung-Shen Chang, Z J Chen, B. Chiaro, J. Claes, Agnetta Y. Cleland, J. G. Cogan, Roberto Collins, P. Conner, W. Courtney, A. L. Crook, Sayan Das, Dripto M. Debroy, Alexander Del Toro Barba, Sean Demura, L. De Lorenzo, Agustín Di Paolo, P. Donohoe, Ilya Drozdov, A. Dunsworth, C. Earle, Alec Eickbusch, A. Elbag, Mahmoud Elzouka, Catherine Erickson, Lara Faoro, R. Fatemi, V. S. Ferreira, Leslie Flores Burgos, Ebrahim Forati, Austin G. Fowler, Brooks Foxen, Suhas Ganjam, Robert Gasca, W. Giang, Craig Gidney, Dar Gilboa, Raja Gosula, Alejandro Grajales Dau, D. Graumann, Alex Greene, Jonathan A. Gross, Steve Habegger, M. Hamilton, M. Hansen, Matthew P. Harrigan, Sean David Harrington, S. Heslin, Paula Heu, G. Hill, J. Hilton, M. R. Hoffmann, Hsin-Yuan Huang, A. Huff, William J. Huggins, L. B. Ioffe, Sergei V. Isakov, Evan R. Jeffrey

Published Jul 2, 2026• 1 citation
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Abstract

Disorder-induced phenomena in quantum many-body systems pose a challenge for analytical and numerical approaches at relevant time and system scales. To reduce the cost of disorder sampling, we investigated quantum circuits initialized in states that form tunable superpositions over all disorder configurations, which in lattice gauge theories can be interpreted as superpositions over gauge sectors. On the experimentally accessible timescales, we observed localization in the absence of disorder in one and two dimensions: Perturbations failed to diffuse despite fully disorder-free evolution and initial states. However, entropy measurements revealed that superposition-prepared states fundamentally differ from those obtained by direct disorder sampling. Leveraging superposition, we propose an algorithm with a polynomial speedup in sampling disorder configurations, a long-standing challenge in many-body localization studies.

DOI
10.1126/science.adr9680

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Disorder-induced phenomena in quantum many-body systems pose a challenge for analytical and numerical approaches at relevant time and system scales. To reduce the cost of disorder sampling, we investigated quantum circuits initialized in states that form tunable superpositions over all disorder configurations, which in lattice gauge theories can be interpreted as superpositions over gauge sectors. On the experimentally accessible timescales, we observed localization in the absence of disorder in one and two dimensions: Perturbations failed to diffuse despite fully disorder-free evolution and initial states. However, entropy measurements revealed that superposition-prepared states fundamentally differ from those obtained by direct disorder sampling. Leveraging superposition, we propose an algorithm with a polynomial speedup in sampling disorder configurations, a long-standing challenge in many-body localization studies.
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Disorder-free localization is a paradigm of nonergodicity in translation-invariant quantum many-body systems hosting gauge symmetries. The quench dynamics starting from simple initial states, which correspond to extensive superpositions of gauge superselection sectors, exhibits many-body localization with the system dynamically inducing its own disorder. An open question concerns the stability of disorder-free localization in the presence of gauge-breaking errors, and whether processes due to the latter can be controllably suppressed. Here, we show that translation-invariant \textit{single-body gauge terms} induce a quantum Zeno effect that reliably protects disorder-free localization against errors up to times at least polynomial in the protection strength. Our experimentally feasible scheme not only shows that disorder-free localization can be reliably stabilized, but also opens promising prospects for its observation in quantum simulators.
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