title: Realization of a Heisenberg XXZ spin system using Rydberg atoms
creator: Ferracini Alves, Renato
subject: ddc-530
subject: 530 Physics
description: In this thesis, we present the realization of an isolated Heisenberg XXZ spin 1/2 system with an off-diagonal  disorder in the coupling constants using cold atoms in highly excited Rydberg states. We select a set of  Rydberg states that interact via van der Waals interaction which can be mapped onto an interacting spin  system. We investigate the out-of-equilibrium dynamics of the spin system after it has been initialized in  a fully magnetized state. Following unitary evolution governed by the Heisenberg spin Hamiltonian, we  measure the magnetization as a function of the evolution time. By fitting a stretched exponential function  to the resulting magnetization dynamics be obtain a stretched exponent of β = 0.32 revealing a slow  relaxation of the spin system, similar to what is found in spin glasses. By choice, the initial state is an  eigenstate of the mean-field Hamiltonian and thus the observed relaxation indicates that the dynamics are  triggered by quantum fluctuations. We find that varying the distribution of coupling constants by means  of the so-called dipole blockade effect has no impact on the stretching exponent indicating that it is  a universal parameter of the system independent of the microscopic details for the range of disorder  explored in the experiment. It also allows us to combine the different datasets by re-scaling the time  domain with the characteristic interaction strength. The combined datasets expand our measurements to  two orders of magnitude in the re-scaled time-domain showing that slow dynamics is a persistent effect  for long evolution times.
date: 2022
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/31511/1/20220413%20renato%20ferracini%20alves%20dissertation%20final.pdf
identifier: DOI:10.11588/heidok.00031511
identifier: urn:nbn:de:bsz:16-heidok-315114
identifier:   Ferracini Alves, Renato  (2022) Realization of a Heisenberg XXZ spin system using Rydberg atoms.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/31511/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng