BEGIN:VCALENDAR VERSION:2.0 PRODID:-//wp-events-plugin.com//6.4.7.2//EN TZID:Europe/Paris X-WR-TIMEZONE:Europe/Paris BEGIN:VEVENT UID:0-1134@lptms.universite-paris-saclay.fr DTSTART;TZID=Europe/Paris:20260914T140000 DTEND;TZID=Europe/Paris:20260914T173000 DTSTAMP:20260717T080214Z URL:https://www.lptms.universite-paris-saclay.fr/seminars/soutenance-de-th ese-gianluca-morettini/ SUMMARY:Soutenance de thèse Gianluca Morettini - Grand amphi\, bâtiment P ascal n° 530 - 14 Sep 26 14:00 DESCRIPTION:Thermalization in one-dimensional quantum many-body systems\nGi anluca Morettini\nThermalization in quantum many-body systems is a central problem of quantum mechanics. Despite the unitary nature of quantum evolu tion\, isolated many-body systems often appear to relax toward states that are locally described by statistical ensembles. However\, phenomena such as integrability and quantum many-body scars demonstrate that thermalizati on is not universal and can fail in unexpected ways\, leading to nonergodi c dynamics and long-lived nonequilibrium behavior. In this thesis\, the pr oblem is addressed from multiple complementary perspectives\, including th ermalization\, integrability breaking\, constrained dynamics\, and quantum many-body scars\, together with the development of new tensor-network met hods for nonequilibrium quantum systems and quantum metrological applicati ons. First\, we study energy-filtering protocols for the preparation of th ermal states\, analyzing the possibility of simulating them classically th rough the behavior of entanglement and correlations. The effects of weak i ntegrability breaking are then investigated in models relevant to Rydberg- atom experiments\, leading to the identification of novel scattering mecha nisms and the introduction of subsystem variance as a sensitive probe of w eak integrability breaking. A part of the thesis is devoted to quantum man y-body scars and their consequences for relaxation and transport phenomena . Their dynamical signatures are studied in both closed and open quantum s ystems\, revealing new mechanisms that sustain long-lived nonequilibrium b ehavior. The thermalization processes arising during the quasi-adiabatic p reparation of the ground state in the trapped Bose–Hubbard model are als o examined\, showing how transport constraints can stabilize low-entropy s tates under experimentally realistic conditions. Finally\, a novel tensor- network approach based on Tree Tensor Operators is introduced for the effi cient computation of the Quantum Fisher Information of generic mixed state s. Applicable to both closed and open quantum systems\, the method provide s a promising numerical tool for quantum sensing and metrological applicat ions.\n\n \;\n\nJury : Mari Carmen Bañuls (rapporteure)\, Leonardo Ma zza (directeur de thèse)\, Davide Rossini (rapporteur)\, Pascal Simon\, J ean-Marie Stéphan CATEGORIES:seminars LOCATION:Grand amphi\, bâtiment Pascal n° 530\, rue André Rivière\, Ors ay\, 91405\, France X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=rue André Rivière\, Orsay \, 91405\, France;X-APPLE-RADIUS=100;X-TITLE=Grand amphi\, bâtiment Pasca l n° 530:geo:0,0 END:VEVENT BEGIN:VTIMEZONE TZID:Europe/Paris X-LIC-LOCATION:Europe/Paris BEGIN:DAYLIGHT DTSTART:20260329T030000 TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST END:DAYLIGHT END:VTIMEZONE END:VCALENDAR