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arXiv · 2601.01309

Hilbert space signatures of non-ergodic glassy dynamics

Aleksey Lunkin·Nicole S. Ticea·Shashwat Kumar·Connie Miao·Jaehong Choi·Mohammed Alghadeer·Ilya Drozdov·Dmitry Abanin·Amira Abbas·Rajeev Acharya·Laleh Beni·Georg Aigeldinger·Ross Alcaraz·Sayra Alcaraz·Markus Ansmann·Frank Arute·Kunal Arya·Walt Askew·Nikita Astrakhantsev·Juan Atalaya·Ryan Babbush·Brian Ballard·Joseph C. Bardin·Hector Bates·Andreas Bengtsson·Majid Karimi·Alexander Bilmes·Simon Bilodeau·Felix Borjans·Alexandre Bourassa·Jenna Bovaird·Dylan Bowers·Leon Brill·Peter Brooks·Michael Broughton·David A. Browne·Brett Buchea·Bob B. Buckley·Tim Burger·Brian Burkett·Nicholas Bushnell·Jamal Busnaina·Anthony Cabrera·Juan Campero·Hung-Shen Chang·Silas Chen·Zijun Chen·Ben Chiaro·Liang-Ying Chih·Agnetta Y. Cleland·Bryan Cochrane·Matt Cockrell·Josh Cogan·Paul Conner·Harold Cook·Rodrigo G. Cortiñas·William Courtney·Alexander L. Crook·Ben Curtin·Martin Damyanov·Sayan Das·Dripto M. Debroy·Sean Demura·Paul Donohoe·Andrew Dunsworth·Valerie Ehimhen·Alec Eickbusch·Aviv Moshe Elbag·Lior Ella·Mahmoud Elzouka·David Enriquez·Catherine Erickson·Lara Faoro·Vinicius S. Ferreira·Marcos Flores·Leslie Burgos·Sam Fontes·Ebrahim Forati·Jeremiah Ford·Brooks Foxen·Masaya Fukami·Alan Wing Fung·Lenny Fuste·Suhas Ganjam·Gonzalo Garcia·Christopher Garrick·Robert Gasca·Helge Gehring·Robert Geiger·William Giang·Dar Gilboa·James E. Goeders·Edward C. Gonzales·Raja Gosula·Stijn J. Graaf·Alejandro Dau·Dietrich Graumann·Joel Grebel·Alex Greene·Jonathan A. Gross
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Abstract

Disorder in quantum many-body systems can drive transitions between ergodic and non-ergodic phases, yet the nature--and even the existence--of these transitions remains intensely debated. Using a two-dimensional array of superconducting qubits, we study an interacting spin model at finite temperature in a disordered landscape, tracking dynamics both in real space and in Hilbert space. Over a broad disorder range, we observe an intermediate non-ergodic regime with glass-like characteristics: physical observables become broadly distributed and some, but not all, degrees of freedom are effectively frozen. The Hilbert-space return probability shows slow power-law decay, consistent with finite-temperature quantum glassiness. In the same regime, we detect the onset of a finite Edwards-Anderson order parameter and the disappearance of spin diffusion. By contrast, at lower disorder, spin transport persists with a nonzero diffusion coefficient. Our results show that there is a transition out of the ergodic phase in two-dimensional systems.

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Aleksey Lunkin, Nicole S. Ticea, Shashwat Kumar, Connie Miao, Jaehong Choi, Mohammed Alghadeer, Ilya Drozdov, Dmitry Abanin, Amira Abbas, Rajeev Acharya, Laleh Beni, Georg Aigeldinger, Ross Alcaraz, Sayra Alcaraz, Markus Ansmann, Frank Arute, Kunal Arya, Walt Askew, Nikita Astrakhantsev, Juan Atalaya, Ryan Babbush, Brian Ballard, Joseph C. Bardin, Hector Bates, Andreas Bengtsson, Majid Karimi, Alexander Bilmes, Simon Bilodeau, Felix Borjans, Alexandre Bourassa, Jenna Bovaird, Dylan Bowers, Leon Brill, Peter Brooks, Michael Broughton, David A. Browne, Brett Buchea, Bob B. Buckley, Tim Burger, Brian Burkett, Nicholas Bushnell, Jamal Busnaina, Anthony Cabrera, Juan Campero, Hung-Shen Chang, Silas Chen, Zijun Chen, Ben Chiaro, Liang-Ying Chih, Agnetta Y. Cleland, Bryan Cochrane, Matt Cockrell, Josh Cogan, Paul Conner, Harold Cook, Rodrigo G. Cortiñas, William Courtney, Alexander L. Crook, Ben Curtin, Martin Damyanov, Sayan Das, Dripto M. Debroy, Sean Demura, Paul Donohoe, Andrew Dunsworth, Valerie Ehimhen, Alec Eickbusch, Aviv Moshe Elbag, Lior Ella, Mahmoud Elzouka, David Enriquez, Catherine Erickson, Lara Faoro, Vinicius S. Ferreira, Marcos Flores, Leslie Burgos, Sam Fontes, Ebrahim Forati, Jeremiah Ford, Brooks Foxen, Masaya Fukami, Alan Wing Fung, Lenny Fuste, Suhas Ganjam, Gonzalo Garcia, Christopher Garrick, Robert Gasca, Helge Gehring, Robert Geiger, William Giang, Dar Gilboa, James E. Goeders, Edward C. Gonzales, Raja Gosula, Stijn J. Graaf, Alejandro Dau, Dietrich Graumann, Joel Grebel, Alex Greene, Jonathan A. Gross. 2026-01-04. Hilbert space signatures of non-ergodic glassy dynamics. https://arxiv.org/abs/2601.01309

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