--- _id: '296' abstract: - lang: eng text: The thermodynamic description of many-particle systems rests on the assumption of ergodicity, the ability of a system to explore all allowed configurations in the phase space. Recent studies on many-body localization have revealed the existence of systems that strongly violate ergodicity in the presence of quenched disorder. Here, we demonstrate that ergodicity can be weakly broken by a different mechanism, arising from the presence of special eigenstates in the many-body spectrum that are reminiscent of quantum scars in chaotic non-interacting systems. In the single-particle case, quantum scars correspond to wavefunctions that concentrate in the vicinity of unstable periodic classical trajectories. We show that many-body scars appear in the Fibonacci chain, a model with a constrained local Hilbert space that has recently been experimentally realized in a Rydberg-atom quantum simulator. The quantum scarred eigenstates are embedded throughout the otherwise thermalizing many-body spectrum but lead to direct experimental signatures, as we show for periodic recurrences that reproduce those observed in the experiment. Our results suggest that scarred many-body bands give rise to a new universality class of quantum dynamics, opening up opportunities for the creation of novel states with long-lived coherence in systems that are now experimentally realizable. acknowledgement: C.J.T., A.M. and Z.P. acknowledge support from EPSRC grants EP/P009409/1 and EP/M50807X/1, and Royal Society Research Grant RG160635. D.A. acknowledges support from the Swiss National Science Foundation. article_processing_charge: No article_type: original author: - first_name: Christopher full_name: Turner, Christopher last_name: Turner - first_name: Alexios full_name: Michailidis, Alexios id: 36EBAD38-F248-11E8-B48F-1D18A9856A87 last_name: Michailidis orcid: 0000-0002-8443-1064 - first_name: Dmitry full_name: Abanin, Dmitry last_name: Abanin - first_name: Maksym full_name: Serbyn, Maksym id: 47809E7E-F248-11E8-B48F-1D18A9856A87 last_name: Serbyn orcid: 0000-0002-2399-5827 - first_name: Zlatko full_name: Papić, Zlatko last_name: Papić citation: ama: Turner C, Michailidis A, Abanin D, Serbyn M, Papić Z. Weak ergodicity breaking from quantum many-body scars. Nature Physics. 2018;14:745-749. doi:10.1038/s41567-018-0137-5 apa: Turner, C., Michailidis, A., Abanin, D., Serbyn, M., & Papić, Z. (2018). Weak ergodicity breaking from quantum many-body scars. Nature Physics. Nature Publishing Group. https://doi.org/10.1038/s41567-018-0137-5 chicago: Turner, Christopher, Alexios Michailidis, Dmitry Abanin, Maksym Serbyn, and Zlatko Papić. “Weak Ergodicity Breaking from Quantum Many-Body Scars.” Nature Physics. Nature Publishing Group, 2018. https://doi.org/10.1038/s41567-018-0137-5. ieee: C. Turner, A. Michailidis, D. Abanin, M. Serbyn, and Z. Papić, “Weak ergodicity breaking from quantum many-body scars,” Nature Physics, vol. 14. Nature Publishing Group, pp. 745–749, 2018. ista: Turner C, Michailidis A, Abanin D, Serbyn M, Papić Z. 2018. Weak ergodicity breaking from quantum many-body scars. Nature Physics. 14, 745–749. mla: Turner, Christopher, et al. “Weak Ergodicity Breaking from Quantum Many-Body Scars.” Nature Physics, vol. 14, Nature Publishing Group, 2018, pp. 745–49, doi:10.1038/s41567-018-0137-5. short: C. Turner, A. Michailidis, D. Abanin, M. Serbyn, Z. Papić, Nature Physics 14 (2018) 745–749. date_created: 2018-12-11T11:45:40Z date_published: 2018-05-14T00:00:00Z date_updated: 2023-09-19T10:37:55Z day: '14' department: - _id: MaSe doi: 10.1038/s41567-018-0137-5 external_id: isi: - '000438253600028' intvolume: ' 14' isi: 1 language: - iso: eng main_file_link: - open_access: '1' url: http://eprints.whiterose.ac.uk/130860/ month: '05' oa: 1 oa_version: Submitted Version page: 745 - 749 publication: Nature Physics publication_status: published publisher: Nature Publishing Group publist_id: '7585' quality_controlled: '1' scopus_import: '1' status: public title: Weak ergodicity breaking from quantum many-body scars type: journal_article user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1 volume: 14 year: '2018' ...