Emergent Bloch Oscillations in a Kinetically Constrained Rydberg Spin Lattice

Abstract

We explore the relaxation dynamics of elementary spin clusters in a kinetically constrained spin system. Inspired by experiments with Rydberg lattice gases, we focus on the situation in which an excited spin leads to a "facilitated" excitation of a neighboring spin. We show that even weak interactions that extend beyond nearest neighbors can have a dramatic impact on the relaxation behavior: they generate a linear potential, which under certain conditions leads to the onset of Bloch oscillations of spin clusters. These hinder the expansion of a cluster and more generally the relaxation of many-body states towards equilibrium. This shows that non-ergodic behavior in kinetically constrained systems may occur as a consequence of the interplay between reduced connectivity of many-body states and weak interparticle interactions. We furthermore show that the emergent Bloch oscillations identified here can be detected in experiment through measurements of the Rydberg atom density, and discuss how spin-orbit coupling between internal and external degrees of freedom of spin clusters can be used to control their relaxation behavior.

Bloch oscillations and the lack of the decay of the false vacuum in a one-dimensional quantum spin chain

“…These appear due to the underlying lattice and the periodicity of the quasiparticles' dispersion relation in the momentum variable. Our observations are in agreement with recent results obtained in kinetically constrained Rydberg spin systems [37]. However, while in Ref.…”

“…However, while in Ref. [37] a special constraint (fine-tuning) was needed to generate Bloch oscillations, here they emerge quite generically, without any constraint in a regime where quasi-particle excitations would naively be expected to speed up and spread correlations over the system.…”

Entanglement generation in $(1+1)D$ QED scattering processes

“…Our work paves the way to future insights into the role played by entanglement in scattering processes in LGTs, extending previous analytical studies and numerical results obtained for spin models [59][60][61][62][63][64]. Moreover, TNs provide the ideal framework and language to make a link between our protocol and experimental quantum simulations and computations of LGTs.…”

Phonon dressing of a facilitated one-dimensional Rydberg lattice gas

“…The results observed in these experiments can be theoretically explained by the presence of a reduced connectivity between different configurations in the Hilbert space [28][29][30][31]. Being first introduced for the study of kinetic aspects in classical glassy systems [32], kinetically constrained systems have been shown to possess peculiar dynamical properties [33][34][35][36], in relation to nucleation and growth processes [37][38][39], the emergence of non-equilibrium phase transitions [40,41], localization [42][43][44] and the absence of relaxation and thermalization in general [45][46][47][48].…”