pith. sign in

arxiv: 2604.12464 · v1 · submitted 2026-04-14 · 🪐 quant-ph · cond-mat.dis-nn· cond-mat.quant-gas

Many-body localization

Pith reviewed 2026-05-10 14:45 UTC · model grok-4.3

classification 🪐 quant-ph cond-mat.dis-nncond-mat.quant-gas
keywords many-body localizationMBLnonergodic dynamicsXXZ modeldisorderthermalizationquantum many-body systemsergodicity breaking
0
0 comments X

The pith

Disorder can localize interacting quantum many-body systems and block thermalization.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This introductory review examines nonergodic behavior in interacting many-body quantum systems, centering on many-body localization. It compiles numerical and theoretical evidence that finite systems undergo a crossover from ergodic, thermalizing dynamics to a localized regime as disorder grows stronger, using the XXZ spin chain as the main example. The discussion then shows the same crossover appears across other models and briefly notes possible links to quantum information storage. A reader would care because the usual expectation is that interactions drive systems toward equilibrium and erase initial conditions, yet MBL suggests disorder can protect coherence indefinitely in certain regimes.

Core claim

Many-body localization is a nonergodic phase in which strong disorder prevents interacting quantum many-body systems from thermalizing, with finite-size simulations of the XXZ model and related Hamiltonians showing a clear crossover from ergodic to localized eigenstate statistics as disorder strength increases.

What carries the argument

Many-body localization (MBL), the mechanism by which disorder localizes many-body eigenstates and suppresses transport and thermalization despite the presence of interactions.

If this is right

  • Finite systems display a disorder-driven crossover from ergodic to MBL regimes, visible in eigenstate properties and dynamics.
  • The MBL crossover and its signatures appear in a range of models beyond the XXZ chain, indicating broad applicability.
  • MBL dynamics may preserve quantum information over long times, opening a connection to quantum computing architectures.
  • Nonergodic behavior challenges the expectation that all interacting closed quantum systems reach thermal equilibrium.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • If the finite-size crossover survives extrapolation to infinite size, MBL could serve as a platform for stable quantum memories that resist decoherence.
  • The review's emphasis on generality suggests MBL may intersect with other ergodicity-breaking mechanisms such as many-body scars or Hilbert-space fragmentation.
  • Experimental platforms like ultracold atoms or trapped ions could directly test the predicted crossover by measuring entanglement growth or transport at varying disorder.

Load-bearing premise

Evidence gathered from finite-size numerical simulations of models such as the XXZ chain reliably reflects the existence and properties of an MBL phase in the infinite thermodynamic limit.

What would settle it

A calculation or experiment on a much larger system size that shows persistent thermalization and delocalized eigenstates even at strong disorder strengths where the finite-size crossover to MBL was previously reported.

read the original abstract

We present an introductory review of nonergodic dynamics in interacting many-body quantum systems, focusing on the phenomenon of many-body localization (MBL). We describe aspects of MBL and summarize the evidence for a crossover from the ergodic to the MBL regime in finite systems, using the paradigmatic XXZ model as an example. We then broaden the scope to other models to illustrate the generality of the phenomenon. We briefly touch on the largely unexplored relation between MBL and quantum computing.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

0 major / 3 minor

Summary. The manuscript is an introductory review of nonergodic dynamics in interacting many-body quantum systems, with a focus on many-body localization (MBL). It describes aspects of MBL and summarizes the evidence for a crossover from the ergodic to the MBL regime in finite systems, using the XXZ model as the primary example. The discussion is then extended to other models to illustrate generality, followed by a brief section on the relation between MBL and quantum computing.

Significance. As a review restricted to finite-size crossovers and the paradigmatic XXZ chain (with extensions to other models), the manuscript offers a clear, accessible entry point to MBL without overclaiming thermodynamic-limit behavior. This framing is a strength, as it aligns with the current state of numerical evidence. The paper accurately frames standard XXZ results and notes the generality across models, providing a useful pedagogical resource for the field.

minor comments (3)
  1. [XXZ model section] The summary of evidence for the ergodic-MBL crossover in the XXZ model would benefit from explicit pointers to the specific observables (e.g., level statistics, entanglement entropy, or imbalance) used in the cited numerical studies.
  2. [quantum computing paragraph] The brief discussion of MBL and quantum computing could include one or two concrete references to recent works on MBL-protected qubits or error correction to strengthen the connection.
  3. [end of manuscript] A short concluding paragraph summarizing the main take-away points on finite-size crossovers would improve the overall structure.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We thank the referee for their careful reading of the manuscript, positive assessment of its scope and framing as an introductory review focused on finite-size crossovers, and recommendation to accept.

Circularity Check

0 steps flagged

No significant circularity: review summarizes external evidence without derivations

full rationale

The manuscript is explicitly framed as an introductory review that describes aspects of MBL and summarizes prior numerical/theoretical evidence for a crossover in finite systems (XXZ model as example), without introducing new derivations, predictions, fitted parameters, or load-bearing claims about the thermodynamic limit. No equations, ansatzes, or self-citations function as self-definitional or fitted-input reductions; the central statements remain descriptive summaries of independent work.

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

As a review paper the central content rests on prior literature rather than new axioms or parameters introduced here.

pith-pipeline@v0.9.0 · 5360 in / 942 out tokens · 22462 ms · 2026-05-10T14:45:49.893040+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Forward citations

Cited by 2 Pith papers

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. The Quantum Kicked Rotor: A Paradigm of Quantum Chaos. Foundational aspects and new perspectives

    quant-ph 2026-04 unverdicted novelty 2.0

    The quantum kicked rotor serves as a unifying model for classical and quantum chaos, covering foundational concepts, experimental realizations, and recent advances in topological and non-Hermitian physics.

  2. Quantum chaotic systems: a random-matrix approach

    quant-ph 2026-04 unverdicted

    Review of random matrix theory application to quantum chaos, covering symmetry classes, eigenvalue statistics, unfolding, and correlation functions.

Reference graph

Works this paper leans on

129 extracted references · 129 canonical work pages · cited by 2 Pith papers

  1. [1]

    Nandkishore and D.A

    R. Nandkishore and D.A. Huse,Many-Body Localization and Thermalization in Quantum Statistical Mechanics,Annual Review of Condensed Matter Physics6(2015) 15

  2. [2]

    Alet and N

    F . Alet and N. Laflorencie,Many-body localization: An introduction and selected topics,Comptes Rendus Physique19(2018) 498

  3. [3]

    Abanin, E

    D.A. Abanin, E. Altman, I. Bloch and M. Serbyn,Colloquium: Many-body localization, thermalization, and entanglement,Rev. Mod. Phys. 91(2019) 021001

  4. [4]

    Gopalakrishnan and S

    S. Gopalakrishnan and S. Parameswaran,Dynamics and transport at the threshold of many-body localization,Physics Reports862 (2020) 1

  5. [5]

    Sierant, M

    P . Sierant, M. Lewenstein, A. Scardicchio, L. Vidmar and J. Zakrzewski,Many-body localization in the age of classical computing*, Reports on Progress in Physics88(2025) 026502

  6. [6]

    Srednicki,The approach to thermal equilibrium in quantized chaotic systems,Journal of Physics A: Mathematical and General32 (1999) 1163

    M. Srednicki,The approach to thermal equilibrium in quantized chaotic systems,Journal of Physics A: Mathematical and General32 (1999) 1163

  7. [7]

    Polkovnikov, K

    A. Polkovnikov, K. Sengupta, A. Silva and M. Vengalattore,Colloquium: Nonequilibrium dynamics of closed interacting quantum systems,Rev. Mod. Phys.83(2011) 863

  8. [8]

    D’Alessio, Y

    L. D’Alessio, Y . Kafri, A. Polkovnikov and M. Rigol,From quantum chaos and eigenstate thermalization to statistical mechanics and thermodynamics,Advances in Physics65(2016) 239

  9. [9]

    Rigol, V

    M. Rigol, V. Dunjko and M. Olshanii,Thermalization and its mechanism for generic isolated quantum systems,Nature452(2008) 854 EP

  10. [10]

    Haake,Quantum Signatures of Chaos, Springer, Berlin (2010)

    F . Haake,Quantum Signatures of Chaos, Springer, Berlin (2010)

  11. [11]

    Oganesyan and D.A

    V. Oganesyan and D.A. Huse,Localization of interacting fermions at high temperature,Phys. Rev. B75(2007) 155111

  12. [12]

    Y .Y . Atas, E. Bogomolny, O. Giraud and G. Roux,Distribution of the ratio of consecutive level spacings in random matrix ensembles, Phys. Rev. Lett.110(2013) 084101

  13. [13]

    Gornyi, A.D

    I.V. Gornyi, A.D. Mirlin and D.G. Polyakov,Interacting Electrons in Disordered Wires: Anderson Localization and Low-TTransport,Phys. Rev. Lett.95(2005) 206603

  14. [14]

    Basko, I

    D. Basko, I. Aleiner and B. Altshuler,Metal-insulator transition in a weakly interacting many-electron system with localized single-particle states,Annals of Physics321(2006) 1126

  15. [15]

    Pal and D.A

    A. Pal and D.A. Huse,Many-body localization phase transition,Phys. Rev. B82(2010) 174411

  16. [16]

    Page,Average entropy of a subsystem,Phys

    D.N. Page,Average entropy of a subsystem,Phys. Rev. Lett.71(1993) 1291

  17. [17]

    Luitz, N

    D.J. Luitz, N. Laflorencie and F . Alet,Many-body localization edge in the random-field Heisenberg chain,Phys. Rev. B91(2015) 081103

  18. [18]

    ˇSuntajs, J

    J. ˇSuntajs, J. Bonˇca, T. Prosen and L. Vidmar,Quantum chaos challenges many-body localization,Phys. Rev. E102(2020) 062144

  19. [19]

    Sierant, D

    P . Sierant, D. Delande and J. Zakrzewski,Thouless Time Analysis of Anderson and Many-Body Localization Transitions,Phys. Rev. Lett. 124(2020) 186601

  20. [20]

    ˇSuntajs, J

    J. ˇSuntajs, J. Bonˇca, T. Prosen and L. Vidmar,Ergodicity breaking transition in finite disordered spin chains,Phys. Rev. B102(2020) 064207

  21. [21]

    Sierant, M

    P . Sierant, M. Lewenstein and J. Zakrzewski,Polynomially filtered exact diagonalization approach to many-body localization,Phys. Rev. Lett.125(2020) 156601

  22. [22]

    Khemani, D.N

    V. Khemani, D.N. Sheng and D.A. Huse,Two universality classes for the many-body localization transition,Phys. Rev. Lett.119(2017) 075702

  23. [23]

    Mac ´e, F

    N. Mac ´e, F . Alet and N. Laflorencie,Multifractal scalings across the many-body localization transition,Phys. Rev. Lett.123(2019) 180601

  24. [24]

    Roy and D.E

    S. Roy and D.E. Logan,The Fock-space landscape of many-body localisation,Journal of Physics: Condensed Matter37(2024) 073003

  25. [25]

    Colbois, F

    J. Colbois, F . Alet and N. Laflorencie,Statistics of systemwide correlations in the random-field xxz chain: Importance of rare events in the many-body localized phase,Phys. Rev. B110(2024) 214210

  26. [26]

    Morningstar, L

    A. Morningstar, L. Colmenarez, V. Khemani, D.J. Luitz and D.A. Huse,Avalanches and many-body resonances in many-body localized systems,Phys. Rev. B105(2022) 174205

  27. [27]

    Sels and A

    D. Sels and A. Polkovnikov,Dynamical obstruction to localization in a disordered spin chain,Phys. Rev. E104(2021) 054105

  28. [28]

    Sels and A

    D. Sels and A. Polkovnikov,Thermalization of dilute impurities in one-dimensional spin chains,Phys. Rev. X13(2023) 011041

  29. [29]

    Zanardi and N

    P . Zanardi and N. Paunkovi´c,Ground state overlap and quantum phase transitions,Phys. Rev. E74(2006) 031123

  30. [30]

    Sierant, A

    P . Sierant, A. Maksymov, M. Ku´s and J. Zakrzewski,Fidelity susceptibility in gaussian random ensembles,Phys. Rev. E99(2019) 050102

  31. [31]

    Serbyn, Z

    M. Serbyn, Z. Papi ´c and D.A. Abanin,Local conservation laws and the structure of the many-body localized states,Phys. Rev. Lett.111 (2013) 127201

  32. [32]

    D.A. Huse, R. Nandkishore and V. Oganesyan,Phenomenology of fully many-body-localized systems,Phys. Rev. B90(2014) 174202

  33. [33]

    Serbyn, Z

    M. Serbyn, Z. Papi ´c and D.A. Abanin,Quantum quenches in the many-body localized phase,Phys. Rev. B90(2014) 174302

  34. [34]

    ˇZnidariˇc, T

    M. ˇZnidariˇc, T. Prosen and P . Prelovˇsek,Many-body localization in the Heisenberg XXZ magnet in a random field,Phys. Rev. B77(2008) 064426

  35. [35]

    Bardarson, F

    J.H. Bardarson, F . Pollmann and J.E. Moore,Unbounded growth of entanglement in models of many-body localization,Phys. Rev. Lett. 14Many-body localization 109(2012) 017202

  36. [36]

    Schreiber, S.S

    M. Schreiber, S.S. Hodgman, P . Bordia, H.P . L¨uschen, M.H. Fischer, R. Vosk et al.,Observation of many-body localization of interacting fermions in a quasirandom optical lattice,Science349(2015) 842

  37. [37]

    Sierant and J

    P . Sierant and J. Zakrzewski,Challenges to observation of many-body localization,Phys. Rev. B105(2022) 224203

  38. [38]

    Laflorencie, J

    N. Laflorencie, J. Colbois and F . Alet,Cat states carrying long-range correlations in the many-body localized phase,Phys. Rev. B112 (2025) 224207

  39. [39]

    Vidmar, B

    L. Vidmar, B. Krajewski, J. Bon ˇca and M. Mierzejewski,Phenomenology of spectral functions in disordered spin chains at infinite temperature,Phys. Rev. Lett.127(2021) 230603

  40. [40]

    Serbyn, Z

    M. Serbyn, Z. Papi ´c and D.A. Abanin,Universal slow growth of entanglement in interacting strongly disordered systems,Phys. Rev. Lett. 110(2013) 260601

  41. [41]

    Schuch, F

    N. Schuch, F . Verstraete and J.I. Cirac,Nonlocal resources in the presence of superselection rules,Phys. Rev. Lett.92(2004) 087904

  42. [42]

    Schuch, F

    N. Schuch, F . Verstraete and J.I. Cirac,Quantum entanglement theory in the presence of superselection rules,Phys. Rev. A70(2004) 042310

  43. [43]

    Kiefer-Emmanouilidis, R

    M. Kiefer-Emmanouilidis, R. Unanyan, M. Fleischhauer and J. Sirker,Evidence for unbounded growth of the number entropy in many-body localized phases,Phys. Rev. Lett.124(2020) 243601

  44. [44]

    Kiefer-Emmanouilidis, R

    M. Kiefer-Emmanouilidis, R. Unanyan, M. Fleischhauer and J. Sirker,Slow delocalization of particles in many-body localized phases, Phys. Rev. B103(2021) 024203

  45. [45]

    Kiefer-Emmanouilidis, R

    M. Kiefer-Emmanouilidis, R. Unanyan, M. Fleischhauer and J. Sirker,Unlimited growth of particle fluctuations in many-body localized phases,Annals of Physics435(2021) 168481

  46. [46]

    Luitz and Y

    D.J. Luitz and Y . Bar Lev,Absence of slow particle transport in the many-body localized phase,Phys. Rev. B102(2020) 100202

  47. [47]

    Ghosh and M

    R. Ghosh and M. ˇZnidariˇc,Resonance-induced growth of number entropy in strongly disordered systems,Phys. Rev. B105(2022) 144203

  48. [48]

    Kiefer-Emmanouilidis, R

    M. Kiefer-Emmanouilidis, R. Unanyan, M. Fleischhauer and J. Sirker,Comment on ”resonance-induced growth of number entropy in strongly disordered systems”, 2022

  49. [49]

    Ghosh and M

    R. Ghosh and M. ˇZnidariˇc,Response to ‘comment on theory of growth of number entropy in disordered systems’, 2022

  50. [50]

    Ch ´avez, C

    D.A. Ch ´avez, C. Artiaco, T.K. Kvorning, L. Herviou and J.H. Bardarson,Ultraslow growth of number entropy in an l-bit model of many-body localization, 2023

  51. [51]

    Evers, I

    F . Evers, I. Modak and S. Bera,Internal clock of many-body delocalization,Phys. Rev. B108(2023) 134204

  52. [52]

    J.-y. Choi, S. Hild, J. Zeiher, P . Schauß, A. Rubio-Abadal, T. Y efsah et al.,Exploring the many-body localization transition in two dimensions,Science352(2016) 1547

  53. [53]

    Y an, H.-Y

    M. Y an, H.-Y . Hui, M. Rigol and V.W. Scarola,Equilibration dynamics of strongly interacting bosons in 2d lattices with disorder,Phys. Rev. Lett.119(2017) 073002

  54. [54]

    J. Hur, J. Li, B. Lee, K. Kwon, M. Kim, S. Hwang et al.,Stability of many-body localization in two dimensions,arXiv e-prints(2025) arXiv:2508.20699 [2508.20699]

  55. [55]

    De Roeck and F

    W. De Roeck and F . Huveneers,Stability and instability towards delocalization in many-body localization systems,Phys. Rev. B95 (2017) 155129

  56. [56]

    Aramthottil, T

    A.S. Aramthottil, T. Chanda, P . Sierant and J. Zakrzewski,Finite-size scaling analysis of the many-body localization transition in quasiperiodic spin chains,Phys. Rev. B104(2021) 214201

  57. [57]

    Falc˜ao, A.S

    P .R.N. Falc˜ao, A.S. Aramthottil, P . Sierant and J. Zakrzewski,Many-body localization crossover is sharper in a quasiperiodic potential, Phys. Rev. B110(2024) 184209

  58. [58]

    Kohlert, S

    T. Kohlert, S. Scherg, X. Li, H.P . L¨uschen, S. Das Sarma, I. Bloch et al.,Observation of many-body localization in a one-dimensional system with a single-particle mobility edge,Phys. Rev. Lett.122(2019) 170403

  59. [59]

    L¨uschen, S

    H.P . L¨uschen, S. Scherg, T. Kohlert, M. Schreiber, P . Bordia, X. Li et al.,Single-particle mobility edge in a one-dimensional quasiperiodic optical lattice,Phys. Rev. Lett.120(2018) 160404

  60. [60]

    Agrawal, R

    U. Agrawal, R. Vasseur and S. Gopalakrishnan,Quasiperiodic many-body localization transition in dimensiond>1,Phys. Rev. B106 (2022) 094206

  61. [61]

    ˇSuntajs and L

    J. ˇSuntajs and L. Vidmar,Ergodicity breaking transition in zero dimensions,Phys. Rev. Lett.129(2022) 060602

  62. [62]

    Pawlik, P

    K. Pawlik, P . Sierant, L. Vidmar and J. Zakrzewski,Many-body mobility edge in quantum sun models,Phys. Rev. B109(2024) L180201

  63. [63]

    ˇSuntajs, M

    J. ˇSuntajs, M. Hopjan, W. De Roeck and L. Vidmar,Similarity between a many-body quantum avalanche model and the ultrametric random matrix model,Phys. Rev. Res.6(2024) 023030

  64. [64]

    De Roeck, F

    W. De Roeck, F . Huveneers, M. M¨uller and M. Schiulaz,Absence of many-body mobility edges,Phys. Rev. B93(2016) 014203

  65. [65]

    van Nieuwenburg, Y

    E. van Nieuwenburg, Y . Baum and G. Refael,From Bloch oscillations to many-body localization in clean interacting systems, Proceedings of the National Academy of Sciences116(2019) 9269

  66. [66]

    Schulz, C.A

    M. Schulz, C.A. Hooley, R. Moessner and F . Pollmann,Stark many-body localization,Phys. Rev. Lett.122(2019) 040606

  67. [67]

    R. Y ao, T. Chanda and J. Zakrzewski,Nonergodic dynamics in disorder-free potentials,Annals of Physics435(2021) 168540

  68. [68]

    Khemani, M

    V. Khemani, M. Hermele and R. Nandkishore,Localization from Hilbert space shattering: From theory to physical realizations,Phys. Rev. B101(2020) 174204

  69. [69]

    P . Sala, T. Rakovszky, R. Verresen, M. Knap and F . Pollmann,Ergodicity Breaking Arising from Hilbert Space Fragmentation in Dipole-Conserving Hamiltonians,Physical Review X10(2020) 011047

  70. [70]

    Pretko, X

    M. Pretko, X. Chen and Y . Y ou,Fracton phases of matter,International Journal of Modern Physics A35(2020) 2030003 [https://doi.org/10.1142/S0217751X20300033]

  71. [71]

    Nandkishore and M

    R.M. Nandkishore and M. Hermele,Fractons,Annual Review of Condensed Matter Physics10(2019) 295 [https://doi.org/10.1146/annurev-conmatphys-031218-013604]

  72. [72]

    Scherg, T

    S. Scherg, T. Kohlert, P . Sala, F . Pollmann, B.H. Madhusudhana, I. Bloch et al.,Observing non-ergodicity due to kinetic constraints in tilted Fermi-Hubbard chains,Nature Communications12(2021)

  73. [73]

    Q. Guo, C. Cheng, H. Li, S. Xu, P . Zhang, Z. Wang et al.,Stark Many-Body Localization on a Superconducting Quantum Processor, Phys. Rev. Lett.127(2021) 240502

  74. [74]

    Morong, F

    W. Morong, F . Liu, P . Becker, K.S. Collins, L. Feng, A. Kyprianidis et al.,Observation of Stark many-body localization without disorder, Nature599(2021) 393

  75. [75]

    Kloss, J.C

    B. Kloss, J.C. Halimeh, A. Lazarides and Y . Bar Lev,Absence of localization in interacting spin chains with a discrete symmetry,Nature Communications14(2023) 3778

  76. [76]

    Zhang,Subdiffusion in strongly tilted lattice systems,Phys

    P . Zhang,Subdiffusion in strongly tilted lattice systems,Phys. Rev. Res.2(2020) 033129

  77. [77]

    Nandy, J

    S. Nandy, J. Herbrych, Z. Lenar ˇciˇc, A. Gł´odkowski, P . Prelovˇsek and M. Mierzejewski,Emergent dipole moment conservation and Many-body localization15 subdiffusion in tilted chains,Phys. Rev. B109(2024) 115120

  78. [78]

    W.-H. Li, X. Deng and L. Santos,Hilbert space shattering and disorder-free localization in polar lattice gases,Phys. Rev. Lett.127(2021) 260601

  79. [79]

    Browaeys and T

    A. Browaeys and T. Lahaye,Many-body physics with individually controlled Rydberg atoms,Nature Physics16(2020) 132

  80. [80]

    Signoles, T

    A. Signoles, T. Franz, R. Ferracini Alves, M. G ¨arttner, S. Whitlock, G. Z¨urn et al.,Glassy Dynamics in a Disordered Heisenberg Quantum Spin System,Phys. Rev. X11(2021) 011011

Showing first 80 references.