Information propagation in the one-dimensional infinite temperature Hubbard model with a dissipative particle sink at the end of a semi-infinite chain is studied. In the strongly interacting limit, the two-site mutual information and the operator entanglement entropy exhibit a rich structure with two propagating information fronts and superimposed interference fringes. A classical reversible cellular automaton model quantitatively captures the transport and the slow, classical part of the correlations but fails to describe the rapidly propagating information jet.
View Article and Find Full Text PDFIn nonequilibrium statistical mechanics, the asymmetric simple exclusion process (ASEP) serves as a paradigmatic example. We investigate the spectral characteristics of the ASEP, focusing on the spectral boundary of its generator matrix. We examine finite ASEP chains of length L, under periodic boundary conditions (PBCs) and open boundary conditions (OBCs).
View Article and Find Full Text PDFUnderstanding universal aspects of quantum dynamics is an unresolved problem in statistical mechanics. In particular, the spin dynamics of the one-dimensional Heisenberg model were conjectured as to belong to the Kardar-Parisi-Zhang (KPZ) universality class based on the scaling of the infinite-temperature spin-spin correlation function. In a chain of 46 superconducting qubits, we studied the probability distribution of the magnetization transferred across the chain's center, [Formula: see text].
View Article and Find Full Text PDFWe introduce and study the discrete-time version of the quantum East model, an interacting quantum spin chain inspired by simple kinetically constrained models of classical glasses. Previous work has established that its continuous-time counterpart displays a disorder-free localization transition signaled by the appearance of an exponentially large (in the volume) family of nonthermal, localized eigenstates. Here we combine analytical and numerical approaches to show that (i) the transition persists for discrete times, in fact, it is present for any finite value of the time step apart from a zero measure set; (ii) it is directly detected by following the nonequilibrium dynamics of the fully polarized state.
View Article and Find Full Text PDFThe validity of the ergodic hypothesis in quantum systems can be rephrased in the form of the eigenstate thermalization hypothesis (ETH), a set of statistical properties for the matrix elements of local observables in energy eigenstates, which is expected to hold in any ergodic system. We test the ETH in a nonintegrable model of relativistic quantum field theory (QFT) using the numerical method of Hamiltonian truncation in combination with analytical arguments based on Lorentz symmetry and renormalization group theory. We find that there is an infinite sequence of eigenstates with the characteristics of quantum many-body scars-that is, exceptional eigenstates with observable expectation values that lie far from thermal values-and we show that these states are one-quasiparticle states.
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