title: Quantum dynamics of disordered many-body spin systems : effects of spatial disorder in a dipolar, frozen gas and influence of spatial inhomogeneity in periodically driven systems
creator: Braemer, Adrian Lukas
subject: ddc-530
subject: 530 Physics
description: In this thesis, we study the thermalization properties in both closed and periodically driven systems subject to spatial inhomogeneities. In Part 1, we focus on long-range Heisenberg spin models of spatially disordered spins which can be realized experimentally by current state-of-the-art platforms. We find numerically that the disordered couplings induced by the randomly positioned spins can lead to a many-body localized regime. Using perturbative arguments based on the real-space renormalization group, we demonstrate that the emergent quasi-conserved quantities arise from pairs of strongly interacting spins decoupling from their environment. Predictions from the resulting effective model of pairs are compared to real experimental data from a Rydberg quantum simulator for validation and are found to be highly accurate. In Part 2, we shift our focus to periodically driven systems which are known to exhibit long-lived (meta-)stable states under certain conditions. Specifically, we consider an ordered Ising chain subject to a driving field of varying strength across different parts of the chain. We demonstrate that a configuration where the driving field has the same strength for all spins except one can dramatically prolong time-crystalline signatures. We link this behavior to the presence of approximate conservation laws stabilized by the spatial inhomogeneity. Additionally, we present preliminary results on the possibility to create a time crystal by driving the pair model derived in the first part.
date: 2024
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserver/35657/1/main_twoside.pdf
identifier: DOI:10.11588/heidok.00035657
identifier: urn:nbn:de:bsz:16-heidok-356570
identifier:   Braemer, Adrian Lukas  (2024) Quantum dynamics of disordered many-body spin systems : effects of spatial disorder in a dipolar, frozen gas and influence of spatial inhomogeneity in periodically driven systems.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/35657/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng