Show simple item record

Files in this item


Item metadata

dc.contributor.advisorHooley, Chris
dc.contributor.advisorMoessner, Roderich
dc.contributor.authorSchulz, Maximilian
dc.coverage.spatialxviii, 178 p.en_US
dc.description.abstractThe study of collective behaviour in many-body systems often explores fundamentally new ideas absent from the mere constituents of such a system. A paradigmatic model for these studies is the spin-1/2 XXZ chain and its fermionic equivalent. This thesis can be broadly divided into the study of two fundamental aspects of this model. Firstly, we discuss localisation phenomena in one dimensional lattices as often experimentally realised in cold atom systems. Secondly, we investigate how disorder and symmetry influence heat transport in spin chains. More specifically, in the first part we consider a system of non-interacting fermions in one dimension subject to a single-particle potential consisting of a strong optical lattice, a harmonic trap, and uncorrelated on-site disorder. We investigate a global inhomogeneous quantum quench and present numerical and analytical results for static and dynamical properties. We show that the approach to the non-thermal equilibrium state is extremely slow and that it implies a sensitivity to disorder parametrically stronger than that expected from Anderson localisation. We also consider the above system in a strong non-uniform electric field. In the non-interacting case, due to Wannier-Stark localisation, the single-particle wave functions are exponentially localised without quenched disorder. We show that this system remains localised in the presence of nearest-neighbour interactions and exhibits physics analogous to models of conventional many-body localisation. The second part explores the hydrodynamics of the disordered XYZ spin chain. Using time-evolving block decimation on open chains of up to 400 spins attached to thermal baths, we probe the energy transport of this system. Our principal findings are as follows. For weak disorder there is a stable diffusive region that persists up to a critical disorder strength that depends on the XY anisotropy. Then, for disorder strengths above this critical value energy transport becomes increasingly subdiffusive.en_US
dc.description.sponsorshipFunded by CM-CDT and EPSRC (UK) under grants EP/G03673X/1 and EP/L015110/1.en
dc.publisherUniversity of St Andrews
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International*
dc.subjectCondensed matteren_US
dc.subjectCold atomsen_US
dc.subjectMany-body localizationen_US
dc.subjectSpin chainsen_US
dc.subject.lcshCondensed matteren
dc.subject.lcshQuantum theoryen
dc.subject.lcshMany-body problemen
dc.titleNon-equilibrium quantum dynamics : interplay of disorder, interactions and confinementen_US
dc.contributor.sponsorEngineering and Physical Sciences Research Council (EPSRC)en_US
dc.contributor.sponsorScottish Doctoral Training Centre in Condensed Matter Physics (CM-CDT)en_US
dc.contributor.sponsorMax-Planck-Gesellschaft zur Förderung der Wissenschaftenen_US
dc.type.qualificationnamePhD Doctor of Philosophyen_US
dc.publisher.institutionThe University of St Andrewsen_US
dc.publisher.departmentMax Planck Institute for the Physics of Complex Systemsen_US

The following license files are associated with this item:

    This item appears in the following Collection(s)

    Show simple item record

    Attribution-NonCommercial-NoDerivatives 4.0 International
    Except where otherwise noted within the work, this item's license for re-use is described as Attribution-NonCommercial-NoDerivatives 4.0 International