---
res:
  bibo_abstract:
  - "Nonergodic systems, whose out-of-equilibrium dynamics fail to thermalize, provide
    a fascinating research direction both for fundamental reasons and for application
    in state of the art quantum devices.\r\nGoing beyond the description of statistical
    mechanics, ergodicity breaking yields a new paradigm in quantum many-body physics,
    introducing novel phases of matter with no counterpart at equilibrium.\r\nIn this
    Thesis, we address different open questions in the field, focusing on disorder-induced
    many-body localization (MBL) and on weak ergodicity breaking in kinetically constrained
    models.\r\nIn particular, we contribute to the debate about transport in kinetically
    constrained models, studying the effect of $U(1)$ conservation and inversion-symmetry
    breaking in a family of quantum East models.\r\nUsing tensor network techniques,
    we analyze the dynamics of large MBL systems beyond the limit of exact numerical
    methods.\r\nIn this setting, we approach the debated topic of the coexistence
    of localized and thermal eigenstates separated by energy thresholds known as many-body
    mobility edges.\r\nInspired by recent experiments, our work further investigates
    the localization of a small bath induced by the coupling to a large localized
    chain, the so-called MBL proximity effect.\r\n\r\nIn the first Chapter, we introduce
    a family of particle-conserving kinetically constrained models, inspired by the
    quantum East model.\r\nThe system we study features strong inversion-symmetry
    breaking, due to the nature of the correlated hopping.\r\nWe show that these models
    host so-called quantum Hilbert space fragmentation, consisting of disconnected
    subsectors in an entangled basis, and further provide an analytical description
    of this phenomenon.\r\nWe further probe its effect on dynamics of simple product
    states, showing revivals in fidelity and local observalbes.\r\nThe study of dynamics
    within the largest subsector reveals an anomalous transient superdiffusive behavior
    crossing over to slow logarithmic dynamics at later times.\r\nThis work suggests
    that particle conserving constrained models with inversion-symmetry breaking realize
    new universality classes of dynamics and invite their further theoretical and
    experimental studies.\r\n\r\nNext, we use kinetic constraints and disorder to
    design a model with many-body mobility edges in particle density.\r\nThis feature
    allows to study the dynamics of localized and thermal states in large systems
    beyond the limitations of previous studies.\r\nThe time-evolution shows typical
    signatures of localization at small densities, replaced by thermal behavior at
    larger densities.\r\nOur results provide evidence in favor of the stability of
    many-body mobility edges, which was recently challenged by a theoretical argument.\r\nTo
    support our findings, we probe the mechanism proposed as a cause of delocalization
    in many-body localized systems with mobility edges suggesting its ineffectiveness
    in the model studied.\r\n\r\nIn the last Chapter of this Thesis, we address the
    topic of many-body localization proximity effect.\r\nWe study a model inspired
    by recent experiments, featuring Anderson localized coupled to a small bath of
    free hard-core bosons.\r\nThe interaction among the two particle species results
    in non-trivial dynamics, which we probe using tensor network techniques.\r\nOur
    simulations show convincing evidence of many-body localization proximity effect
    when the bath is composed by a single free particle and interactions are strong.\r\nWe
    furthter observe an anomalous entanglement dynamics, which we explain through
    a phenomenological theory.\r\nFinally, we extract highly excited eigenstates of
    large systems, providing supplementary evidence in favor of our findings.@eng"
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Pietro
      foaf_name: Brighi, Pietro
      foaf_surname: Brighi
      foaf_workInfoHomepage: http://www.librecat.org/personId=4115AF5C-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0002-7969-2729
  bibo_doi: 10.15479/at:ista:12732
  dct_date: 2023^xs_gYear
  dct_isPartOf:
  - http://id.crossref.org/issn/2663-337X
  dct_language: eng
  dct_publisher: Institute of Science and Technology Austria@
  dct_title: Ergodicity breaking in disordered and kinetically constrained quantum
    many-body systems@
...