Frustrated Magnetism and Localization in a Long-Range Interacting Spin System

Frustration, bond disorder, and long-range interactions can produce novel, highly nontrivial phases of matter. This thesis investigates a bond-disordered, dipolar-interacting XY spin model, studied through both numerical simulations and experiments on a Rydberg quantum simulator. Three major results are achieved: (i) We analyze energetic-magnetic hysteresis in two disorder configurations, and find pronounced hysteresis in the strongly disordered configuration for low energies. This is a first experimental evidence of energetic-magnetic hysteresis in putative isolated glasses. (ii) We develop an extension of the generalized Kibble-Zurek mechanism for reverse quenches, which allows to characterize putative spin glass quantum phase transitions by global magnetization measurements. We validate this extension numerically exactly for one-dimensional systems, and subsequently experimentally extract a critical exponent consistent with spin glass critical exponents measured in other systems. This is a first tentative experimental evidence of a spin glass phase in an isolated dipolar interacting spin system. (iii) We studied time reversal on a Rydberg quantum simulator and showed numerically that, in bond-disordered power-law interacting models, time-reversal–based protocols reveal a localization mechanism distinct from conventional many-body localization at finite sizes.