Enhancing Disorder-Free Localization through Dynamically Emergent Local Symmetries

Year: 2022

Authors: Halimeh J.C., Homeier L., Zhao H., Bohrdt A., Grusdt F., Hauke P., Knolle J.

Autors Affiliation: INO-CNR BEC Center and Department of Physics, University of Trento, Via Sommarive 14, Trento I-38123, Italy; Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universitdt M

Abstract: Disorder-free localization is a recently discovered phenomenon of nonergodicity that can emerge in quantum many-body systems hosting gauge symmetries when the initial state is prepared in a superposition of gauge superselection sectors. Thermalization is then prevented up to all accessible evolution times despite the model being nonintegrable and translation invariant. In a recent work [Halimeh et al., arXiv:2111.02427 (2021)], it has been shown that terms linear in the gauge-symmetry generator stabilize disorder-free localization in U(1) gauge theories against gauge errors that couple different superselection sectors. Here, we show in the case of Z2 gauge theories that disorder-free localization can not only be stabilized, but also enhanced by the addition of translation-invariant terms linear in a local Z2 pseudogenerator that acts identically to the full generator in a single superselection sector, but not necessarily outside of it. We show analytically and numerically how this leads through the quantum Zeno effect to the dynamical emergence of a renormalized gauge theory with an enhanced local symmetry, which contains the Z2 gauge symmetry of the ideal model, associated with the Z2 pseudogenerator. The resulting proliferation of superselection sectors due to this dynamically emergent gauge theory creates an effective disorder greater than that in the original model, thereby enhancing disorder-free localization. We demonstrate the experimental feasibility of the Z2 pseudogenerator by providing a detailed readily implementable experimental proposal for the observation of disorder-free localization in a Rydberg setup.

Journal/Review: PRX QUANTUM

Volume: 3 (2)      Pages from: 020345-1  to: 020345-19

More Information: J.C.H. is grateful to Ian P. McCulloch for a thorough reading of and valuable comments on our manuscript. The authors are grateful to Monika Aidelsburger, Debasish Banerjee, Sepehr Ebadi, Arkady Fedorov, Ognjen Markovic, Ian P. McCulloch, and Christian Schweizer for fruitful discussions. This work is part of and supported by Provincia Autonoma di Trento, the ERC Starting Grant StrEnQTh (project ID 804305), the Google Research Scholar Award ProGauge, and Q@TN-Quantum Science and Technology in Trento. H.Z. acknowledges support from a Doctoral-Program Fellowship of the German Academic Exchange Service (DAAD). This research is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany´s Excellence Strategy-EXC-2111-390814868 and via DFG Research Unit FOR 2414 under Project No. 277974659. This project has received funding from the European Research Council (ERC) under the European Union´s Horizon 2020 research and innovation programm (Grant Agreement No. 948141). We acknowledge support from the Imperial-TUM flagship partnership. L.H. acknowledges support from the Studienstiftung des deutschen Volkes. A.B. acknowledges support from the National Science Foundation (NSF) through a grant for the Institute for Theoretical Atomic, Molecular, and Optical Physics at Harvard University and the Smithsonian Astrophysical Observatory.
DOI: 10.1103/PRXQuantum.3.020345