Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1410.4690 · Physical Review B

Dynamics in many-body localized quantum systems without disorder

Mauro Schiulaz, Alessandro Silva, Markus Müller

Published May 6, 2015• 139 citations
arXivHTMLPDF

Abstract

We study the relaxation dynamics of strongly interacting quantum systems that display a kind of many-body localization in spite of their translation-invariant Hamiltonian. We show that dynamics starting from a random initial configuration is nonperturbatively slow in the hopping strength, and potentially genuinely nonergodic in the thermodynamic limit. In finite systems with periodic boundary conditions, density relaxation takes place in two stages, which are separated by a long out-of-equilibrium plateau whose duration diverges exponentially with the system size. We estimate the phase boundary of this quantum glass phase, and discuss the role of local resonant configurations. We suggest experimental realizations and methods to observe the discussed nonergodic dynamics.

DOI
10.1103/physrevb.91.184202

Related papers

Observation of many-body localization of interacting fermions in a quasirandom optical lattice

Michael Schreiber, Sean S. Hodgman, Pranjal Bordia +6 more

Many-body localization (MBL), the disorder-induced localization of interacting particles, signals a breakdown of conventional thermodynamics because MBL systems do not thermalize and show nonergodic time evolution. We experimentally observed this nonergodic evolution for interacting fermions in a one-dimensional quasirandom optical lattice and identified the MBL transition through the relaxation dynamics of an initially prepared charge density wave. For sufficiently weak disorder, the time evolution appears ergodic and thermalizing, erasing all initial ordering, whereas above a critical disorder strength, a substantial portion of the initial ordering persists. The critical disorder value shows a distinctive dependence on the interaction strength, which is in agreement with numerical simulations. Our experiment paves the way to further detailed studies of MBL, such as in noncorrelated disorder or higher dimensions.

arXiv:1501.05661•Science•Jul 30, 2015•1,722 citations

Probing many-body localization with ultracold atoms in optical lattices

Pranjal Bordia

This thesis reports on first experiments on the observation of ergodicity breaking in a two-component, interacting fermionic gas of Potassium-40 subject to quasi-periodic optical lattices in one and two dimensions, demonstrating the breakdown of thermalization in highly excited states of isolated quantum systems. Our observations can be explained by the phenomenon of many-body localization, a non-ergodic phase of matter, whose properties can be detected with non-equilibrium probes. To probe such a phase, we first design a far-from-equilibrium initial state and then monitor how much the system remembers of this design during time evolution. This allows us to identify regimes and timescales where disorder can protect local quantum information and distinguish such cases from regimes where interactions amalgamate local information into highly nonlocal quantum correlations. We then describe how this treatment systematically breaks down in all real-world systems as the system is (necessarily) coupled to some bath-like structure. Following very recent developments, we are further able to show that order can exist even in driven quantum systems, which were earlier thought to exhibit no interesting features, corresponding to an infinite temperature state. We also extend the experimental realm to explore two dimensions and show that the dynamics emerge as a distinct interplay of interactions, disorder, and dimensions. Upon probing a putative MBL transition, we further show signatures of a new kind of slow relaxation, potentially arising due to randomness in the initial state. We close with some theoretical results on probing quantum dynamics ensuing in the absence of transport and a discussion of exciting areas for future experiments.

•Jan 1, 2017•0 citations

Dynamics of many-body localization in a translation-invariant quantum glass model

Merlijn van Horssen, Emanuele Levi, Juan P. Garrahan

The authors present evidence of many-body localization in a translationally invariant model Hamiltonian. The model, Ising-like, arises in the study of quantum glasses. The authors show that this model exhibits two regimes: one of fast relaxation and one of slow relaxation with dynamical features typically associated with many-body localized phases.

arXiv:1505.07089•Physical Review B•Sep 28, 2015•155 citations

Kohlrausch regime of slow relaxation and its phenomenology in isolated quantum many-body systems with strong disorder

Asmi Haldar

The Kohlrausch(-Williams-Watts) law of stretched exponential relaxation has been observed for over a century and a half in diverse complex classical systems. Here we show that this law describes relaxation quite generically in closed (executing Schrödinger dynamics), interacting disordered many-body systems, using interaction range and disorder strength as primary tuning parameters. This we observe for both time-independent and periodically driven (Floquet) systems. Finite-size analysis indicates the persistence of this nonthermal relaxation regime in the thermodynamic limit thus defining a distinct dynamical regime. This regime exhibits a peak in the time scale of the long-time relaxation (following a transient), upon crossing over from weak to strong disorder. We provide a simple picture of this behavior, which naturally accounts for its generic occurrence. Formation of spin-glass — one of the possible mechanisms for stretched relaxation appears incidental to the occurrence of Kohlrausch law in our context. Finally, we provide a simple non-Hermitian Hamiltonian formulation for the dynamics of a single spin embedded in the disordered chain. This provides an analytical formula that captures not only the Kohlrausch relaxation of the disorder averaged autocorrelation but also captures the largely diverse dynamics of an arbitrary target spin in the system. Our work hence also provides a concrete quantification of the “prethermal slowness” in many-body disordered system.

arXiv:2302.12275•Physical review. B./Physical review. B•Feb 5, 2025•4 citations

Observation of Slow Dynamics near the Many-Body Localization Transition in One-Dimensional Quasiperiodic Systems

Henrik P. Lüschen, Pranjal Bordia, Sebastian Scherg +4 more

In the presence of sufficiently strong disorder or quasiperiodic fields, an interacting many-body system can fail to thermalize and become many-body localized. The associated transition is of particular interest, since it occurs not only in the ground state but over an extended range of energy densities. So far, theoretical studies of the transition have focused mainly on the case of true-random disorder. In this work, we experimentally and numerically investigate the regime close to the many-body localization transition in quasiperiodic systems. We find slow relaxation of the density imbalance close to the transition, strikingly similar to the behavior near the transition in true-random systems. This dynamics is found to continuously slow down upon approaching the transition and allows for an estimate of the transition point. We discuss possible microscopic origins of these slow dynamics.

arXiv:1612.07173•Physical Review Letters•Dec 27, 2017•281 citations

Stability and quasi-periodicity of many-body localized dynamics

Peyman Azodi, HERSCHEL A. RABITZ

Abstract The connection between entanglement dynamics and non-equilibrium statistics in isolated many-body quantum systems has been established both theoretically and experimentally. Many-body localization (MBL), a phenomenon where interacting particles in disordered (i.e. random) chains fail to thermalize, exemplifies this connection. However, the systematic proof of critical phenomena such as MBL remains challenging due to the lack of robust methods for analyzing many-body entanglement dynamics. In this paper, we identify MBL through quasi-periodic dynamics in the entanglement evolution of subsystems in a disordered Heisenberg chain. This new form of characterizing MBL, through stable quasi-periodic dynamics of entanglement-where ‘stable’ means they persist in the thermodynamic limit—concretely distinguishes between two competing scenarios: fully localized behavior of subsystems or slowly, exponentially slow in disorder, thermalizing subsystems—a heated controversy in the literature. Utilizing perturbation theory, we derive the entanglement dynamics of single spins through an infinite perturbative series, while also modeling rare Griffiths regions (locally thermal inclusions). Our results prove that in regimes of sufficiently strong disorder, the entanglement evolution of individual subsystems remains quasi-periodic in the thermodynamic limit, thereby providing concrete evidence for the stability of MBL dynamics in disordered Heisenberg chains. This behavior contrasts with the widely reported logarithmic growth of subsystem entanglement in the MBL phase. We show that the logarithmic growth observed in prior studies arises from statistical ensemble averaging, which is prohibited due to the intrinsic non-ergodic dynamics characteristic of MBL systems, rooted in their quasi-periodic features.

arXiv:2201.11223•New Journal of Physics•Jul 1, 2025•1 citation
We study the relaxation dynamics of strongly interacting quantum systems that display a kind of many-body localization in spite of their translation-invariant Hamiltonian. We show that dynamics starting from a random initial configuration is nonperturbatively slow in the hopping strength, and potentially genuinely nonergodic in the thermodynamic limit. In finite systems with periodic boundary conditions, density relaxation takes place in two stages, which are separated by a long out-of-equilibrium plateau whose duration diverges exponentially with the system size. We estimate the phase boundary of this quantum glass phase, and discuss the role of local resonant configurations. We suggest experimental realizations and methods to observe the discussed nonergodic dynamics.
Many-body localization (MBL), the disorder-induced localization of interacting particles, signals a breakdown of conventional thermodynamics because MBL systems do not thermalize and show nonergodic time evolution. We experimentally observed this nonergodic evolution for interacting fermions in a one-dimensional quasirandom optical lattice and identified the MBL transition through the relaxation dynamics of an initially prepared charge density wave. For sufficiently weak disorder, the time evolution appears ergodic and thermalizing, erasing all initial ordering, whereas above a critical disorder strength, a substantial portion of the initial ordering persists. The critical disorder value shows a distinctive dependence on the interaction strength, which is in agreement with numerical simulations. Our experiment paves the way to further detailed studies of MBL, such as in noncorrelated disorder or higher dimensions.
This thesis reports on first experiments on the observation of ergodicity breaking in a two-component, interacting fermionic gas of Potassium-40 subject to quasi-periodic optical lattices in one and two dimensions, demonstrating the breakdown of thermalization in highly excited states of isolated quantum systems. Our observations can be explained by the phenomenon of many-body localization, a non-ergodic phase of matter, whose properties can be detected with non-equilibrium probes. To probe such a phase, we first design a far-from-equilibrium initial state and then monitor how much the system remembers of this design during time evolution. This allows us to identify regimes and timescales where disorder can protect local quantum information and distinguish such cases from regimes where interactions amalgamate local information into highly nonlocal quantum correlations. We then describe how this treatment systematically breaks down in all real-world systems as the system is (necessarily) coupled to some bath-like structure. Following very recent developments, we are further able to show that order can exist even in driven quantum systems, which were earlier thought to exhibit no interesting features, corresponding to an infinite temperature state. We also extend the experimental realm to explore two dimensions and show that the dynamics emerge as a distinct interplay of interactions, disorder, and dimensions. Upon probing a putative MBL transition, we further show signatures of a new kind of slow relaxation, potentially arising due to randomness in the initial state. We close with some theoretical results on probing quantum dynamics ensuing in the absence of transport and a discussion of exciting areas for future experiments.
The Kohlrausch(-Williams-Watts) law of stretched exponential relaxation has been observed for over a century and a half in diverse complex classical systems. Here we show that this law describes relaxation quite generically in closed (executing Schrödinger dynamics), interacting disordered many-body systems, using interaction range and disorder strength as primary tuning parameters. This we observe for both time-independent and periodically driven (Floquet) systems. Finite-size analysis indicates the persistence of this nonthermal relaxation regime in the thermodynamic limit thus defining a distinct dynamical regime. This regime exhibits a peak in the time scale of the long-time relaxation (following a transient), upon crossing over from weak to strong disorder. We provide a simple picture of this behavior, which naturally accounts for its generic occurrence. Formation of spin-glass — one of the possible mechanisms for stretched relaxation appears incidental to the occurrence of Kohlrausch law in our context. Finally, we provide a simple non-Hermitian Hamiltonian formulation for the dynamics of a single spin embedded in the disordered chain. This provides an analytical formula that captures not only the Kohlrausch relaxation of the disorder averaged autocorrelation but also captures the largely diverse dynamics of an arbitrary target spin in the system. Our work hence also provides a concrete quantification of the “prethermal slowness” in many-body disordered system.
In the presence of sufficiently strong disorder or quasiperiodic fields, an interacting many-body system can fail to thermalize and become many-body localized. The associated transition is of particular interest, since it occurs not only in the ground state but over an extended range of energy densities. So far, theoretical studies of the transition have focused mainly on the case of true-random disorder. In this work, we experimentally and numerically investigate the regime close to the many-body localization transition in quasiperiodic systems. We find slow relaxation of the density imbalance close to the transition, strikingly similar to the behavior near the transition in true-random systems. This dynamics is found to continuously slow down upon approaching the transition and allows for an estimate of the transition point. We discuss possible microscopic origins of these slow dynamics.
Abstract The connection between entanglement dynamics and non-equilibrium statistics in isolated many-body quantum systems has been established both theoretically and experimentally. Many-body localization (MBL), a phenomenon where interacting particles in disordered (i.e. random) chains fail to thermalize, exemplifies this connection. However, the systematic proof of critical phenomena such as MBL remains challenging due to the lack of robust methods for analyzing many-body entanglement dynamics. In this paper, we identify MBL through quasi-periodic dynamics in the entanglement evolution of subsystems in a disordered Heisenberg chain. This new form of characterizing MBL, through stable quasi-periodic dynamics of entanglement-where ‘stable’ means they persist in the thermodynamic limit—concretely distinguishes between two competing scenarios: fully localized behavior of subsystems or slowly, exponentially slow in disorder, thermalizing subsystems—a heated controversy in the literature. Utilizing perturbation theory, we derive the entanglement dynamics of single spins through an infinite perturbative series, while also modeling rare Griffiths regions (locally thermal inclusions). Our results prove that in regimes of sufficiently strong disorder, the entanglement evolution of individual subsystems remains quasi-periodic in the thermodynamic limit, thereby providing concrete evidence for the stability of MBL dynamics in disordered Heisenberg chains. This behavior contrasts with the widely reported logarithmic growth of subsystem entanglement in the MBL phase. We show that the logarithmic growth observed in prior studies arises from statistical ensemble averaging, which is prohibited due to the intrinsic non-ergodic dynamics characteristic of MBL systems, rooted in their quasi-periodic features.