--- res: bibo_abstract: - 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.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Christopher foaf_name: Turner, Christopher foaf_surname: Turner - foaf_Person: foaf_givenName: Alexios foaf_name: Michailidis, Alexios foaf_surname: Michailidis foaf_workInfoHomepage: http://www.librecat.org/personId=36EBAD38-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-8443-1064 - foaf_Person: foaf_givenName: Dmitry foaf_name: Abanin, Dmitry foaf_surname: Abanin - foaf_Person: foaf_givenName: Maksym foaf_name: Serbyn, Maksym foaf_surname: Serbyn foaf_workInfoHomepage: http://www.librecat.org/personId=47809E7E-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-2399-5827 - foaf_Person: foaf_givenName: Zlatko foaf_name: Papić, Zlatko foaf_surname: Papić bibo_doi: 10.1038/s41567-018-0137-5 bibo_volume: 14 dct_date: 2018^xs_gYear dct_identifier: - UT:000438253600028 dct_language: eng dct_publisher: Nature Publishing Group@ dct_title: Weak ergodicity breaking from quantum many-body scars@ ...