Article
Physics, Multidisciplinary
Lev Vidmar, Bartosz Krajewski, Janez Bonca, Marcin Mierzejewski
Summary: Recent research on disordered spin chains has focused on the relationship between exact numerical calculations and the existence of a many-body localization phase transition, particularly in cases where disorder is significantly greater than spin interaction strength. A phenomenological theory based on proximity to the noninteracting limit, such as the Anderson insulator, has been introduced to explain intriguing features observed in these systems. This theory quantitatively describes the dynamics of certain observables in finite interacting systems across a wide range of disorders.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Julian Siegl, John Schliemann
Summary: We investigate many-body localization in isotropic Heisenberg spin chains with quenched disorder. The nonabelian symmetry in their Hamiltonian is found to hinder the emergence of a many-body localized phase even in the presence of strong disorder. We report a transition from an ergodic phase to an incompletely localized phase at stronger disorder and distinguish this phase from the fully many-body localized phase based on its scaling behavior.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Dries Sels, Anatoli Polkovnikov
Summary: We investigate the crossover from ergodic to nonergodic behavior in an interacting spin chain with sparse impurity density. By studying the relaxation and delocalization of these impurities, we find that they always exchange energy with the rest of the chain, leading to weakly dependent relaxation rates and exponential decay with field strength. This relaxation is connected to operator spreading and hinders the construction of local integrals of motion. In the high field limit, the impurities appear localized, but eventual delocalization occurs due to a flowing localization length.
Article
Materials Science, Multidisciplinary
Aaron J. Friedman, Brayden Ware, Romain Vasseur, Andrew C. Potter
Summary: We construct an example of a 1d quasiperiodically driven spin chain that has edge states protected by a combination of localization, dynamics, and topology. The protection of the edge states is purely based on emergent dynamical symmetries, rather than microscopic symmetry protection. We investigate the dynamical signatures of this emergent dynamical symmetry-protected topological (EDSPT) order through computational methods and find evidence of its stability against bulk many-body localization.
Article
Materials Science, Multidisciplinary
Bartosz Krajewski, Marcin Mierzejewski, Janez Bonca
Summary: This study investigates the sample-to-sample fluctuations of the gap ratio in the energy spectra of finite disordered spin chains. It is found that the fluctuations in the microscopic models significantly exceed those in the Rosenzweig-Porter (RP) model near the ergodic-nonergodic crossover. By introducing an extension to the RP model, the fluctuations in all regimes, including the ergodic and nonergodic regimes as well as the crossover between them, can be accurately reproduced. Furthermore, this study demonstrates methods to reduce the sample-to-sample fluctuations in both studied microscopic models.
Article
Mathematics, Applied
Xiansong Xu, Dario Poletti
Summary: The study reveals that the natural orbitals of the steady state single-particle density matrix are localized for both weak and strong interactions in the presence of strong disorder. In contrast, the steady-state occupation tends to be more evenly spread with strong disorder or stronger interactions. Strong dissipation increases coherence of the steady states, leading to reduced localization signatures.
Article
Physics, Mathematical
Bruno Nachtergaele, Jake Reschke
Summary: The study explores the relationship between transmission time, Local Integrals of Motion (LIOM), and many-body localization properties in disordered quantum spin chains. Results show various implications of different forms of dynamical localization on the dynamics and transmission times in the spin chains.
JOURNAL OF STATISTICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Devendra Singh Bhakuni, Lea F. Santos, Yevgeny Bar Lev
Summary: A mechanism to suppress heating in periodically driven many-body quantum systems is proposed, utilizing long-range interactions and relevant initial conditions. Decreasing the driving frequency can reduce heating and entanglement buildup in these systems. This mechanism is robust to local perturbations and can be generalized to higher dimensions.
Article
Materials Science, Multidisciplinary
Christopher M. Langlett, Shenglong Xu
Summary: This work introduces a family of spin-1/2 many-body Hamiltonians based on the Fredkin spin chain, featuring a fragmented Hilbert space and quantum many-body scars. Exact middle spectrum eigenstates are constructed to demonstrate logarithmic or area-law entanglement entropy within each fractured subsector. The interplay between fragmentation and scarring results in rich tunable nonergodic dynamics.
Article
Physics, Multidisciplinary
Pai Peng, Chao Yin, Xiaoyang Huang, Chandrasekhar Ramanathan, Paola Cappellaro
Summary: Periodically driven Floquet quantum systems can enter a long-lived prethermal regime at high driving frequencies, with an exponentially slow heating rate. Experimental observation of prethermalization and other properties of Floquet systems demonstrate the potential for realizing non-trivial Floquet phases of matter.
Article
Materials Science, Multidisciplinary
T. Boorman, M. Szyniszewski, H. Schomerus, A. Romito
Summary: We analyze the generation and destruction of entanglement in a one-dimensional quantum spin chain under locally noisy and disordered Hamiltonian using the concept of a measurement-induced entanglement transition. By continuously measuring the system, we induce a transition from volume to area-law scaling of the steady-state entanglement entropy. The critical measurement strength is systematically reduced by static background disorder, but the dependence on the strength of nonstatic noise is nonmonotonic. According to the extracted finite-size scaling exponents, the universality class of the transition is independent of the noise and disorder strength.
Article
Materials Science, Multidisciplinary
Dries Sels
Summary: This Letter provides numerical evidence for the dynamics of disordered spin chains weakly coupled to a Markovian bath, showing that the critical disorder for stability to quantum avalanches drifts considerably with system size, with no evidence of saturation in the studied regime.
Article
Multidisciplinary Sciences
Benedikt Kloss, Jad C. Halimeh, Achilleas Lazarides, Yevgeny Bar Lev
Summary: Kloss et al theoretically and numerically establish the absence of many-body localization in a broad class of spin models that respect certain symmetries.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
R. B. Versteeg, A. Chiocchetta, F. Sekiguchi, A. Sahasrabudhe, J. Wagner, A. I. R. Aldea, K. Budzinauskas, Zhe Wang, V. Tsurkan, A. Loidl, D. I. Khomskii, S. Diehl, P. H. M. van Loosdrecht
Summary: In this study, we modify the magnetic free energy landscape and phase diagram of the frustrated honeycomb magnet ??-RuCl3 by photoexciting high-energy holon-doublon pairs. The recombination process of the pairs through multimagnon emission is observed through the time evolution of the magnetooptical response. Our findings suggest a new route to achieve a nontrivial spin-disordered state in Kitaev-like magnets.
Article
Quantum Science & Technology
Christopher L. Baldwin, Adam Ehrenberg, Andrew Y. Guo, Alexey V. Gorshkov
Summary: By tightening the conventional Lieb-Robinson bounds, we analyze the effect of weak links on operator growth in disordered one-dimensional spin chains. We prove that ballistic growth is impossible when the distribution of coupling strengths has a sufficiently heavy tail at small coupling strengths. We also find that the standard formulation of Lieb-Robinson bounds is insufficient to capture the complexity of the dynamics in certain cases.
