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REVIEW 4 major objections 4 minor 67 references

Spin and energy diffusion vs. subdiffusion in disordered spin chains

T0 review · 4 major / 4 minor · reviewed 2026-08-16 · deepseek-v4-flash

Pith's one-line read At strong random fields, the disordered Heisenberg spin chain is subdiffusive rather than localized, with spin and energy diffusion exponentially small, nearly equal, and incompatible with the Thouless localization criterion at reachable…

desk verdict Most direct comparison to date of spin vs energy diffusion in the random-field XXZ chain, with a clean new Einstein relation for energy diffusion and a robust negative result on the Thouless criterion; the subdiffusion claim is plausible but not nailed down. read the letter →

arxiv 2504.15705 v2 pith:F7X2L5FB submitted 2025-04-22 cond-mat.dis-nn cond-mat.str-el

classification cond-mat.dis-nncond-mat.str-el
keywords many-bodylocalizationsubdiffusionspindiffusionenergyThoulesscriterionrandomHeisenbergchainGriffithseffectsquasiperiodicpotential
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper asks whether the random-field Heisenberg spin chain, the standard model for many-body localization (MBL), actually localizes at strong disorder or merely becomes extremely slow. It establishes that at disorder strengths $W\gtrsim 2$ the d.c. spin and energy diffusion constants are exponentially small and essentially equal, $D_s^0 \simeq D_e^0 \propto \exp(-bW/J)$ with $b\simeq 2.5$, and it derives an Einstein relation for energy diffusion that puts the two channels on the same footing. It then argues that this exponential smallness is not localization: the flux sensitivity $R$ stays above the Thouless threshold $R=1$ and grows with system size, while the dynamical diffusivity behaves as $D(\omega)\simeq D_0+c|\omega|^\alpha$ with $\alpha<1$ at large $W$. If correct, the slowest relaxation time in the system is set equally by spin and energy transport, and the MBL phase, if it exists, has not been reached at the numerically accessible sizes.

What carries the argument

The argument is carried by three linked objects. First, Einstein relations express the spin and energy diffusivities as current-correlation functions, $D_s(\omega)=\pi\langle j_s j_s\rangle_\omega/(L\tilde\chi_s^0)$ and the analogous $D_e(\omega)$, with the static energy susceptibility $\tilde\chi_e^0 = J^2/8 + J^2\Delta^2/16 + W^2/12$; this lets energy diffusion be computed with the same accuracy as spin diffusion. Second, the level sensitivity $R = \delta\varphi\,\sqrt{(j^s_{nn})^2}/\Delta_e$ compares flux-induced level shifts to the mean level spacing, providing the Thouless criterion $R<1$ for localization and a marker of when random-matrix universality breaks down. Third, the low-frequency fit $D(\omega)-D_0 \simeq c|\omega|^\alpha$ distinguishes subdiffusion ($\alpha<1$, diverging d.c. polarizability) from diffusion ($\alpha=1$) or localization ($\alpha>1$).

What would settle it

Compute the dynamical diffusivity at higher frequency resolution ($\delta\omega\ll 10^{-4}$) and on larger systems: if the fitted exponent $\alpha$ moves to 1 while $D_0(L)$ saturates rather than continuing to decrease, the subdiffusion claim is falsified; observing $\alpha>1$ with a systematically decreasing $D_0$ would support an MBL transition instead.

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Extended reading notes

Core claim

The paper's central claim is that in the high-temperature XXZ chain with random fields, strong disorder produces a subdiffusive regime rather than a many-body localized state. The d.c. spin and energy diffusion constants both decrease exponentially with disorder, $D_s^0 \sim D_e^0 \sim \exp(-bW/J)$ with $b\simeq 2.5$, and become numerically equal for $W\gtrsim 2$; the paper shows the near equality follows from the energy current being dominated at large $W$ by $(w_l+w_{l+1})/2$ times the local spin current. Two finite-size tests point away from a true localized phase: the level sensitivity $R$ to twisted boundary conditions remains larger than one up to $L=28$ and increases with $L$, which violates the Thouless condition $R<1$ for localization, and the low-frequency diffusivity follows $D(\omega)\simeq D_0+c|\omega|^\alpha$ with $\alpha<1$ for random fields, the signature of subdiffusion, while quasiperiodic fields give $\alpha\gtrsim 1$.

Load-bearing premise

The load-bearing premise is that the frequency window $0<\omega<0.05$ resolved at $\delta\omega\sim 10^{-4}$ and system sizes up to $L=28$ already show the asymptotic scaling $D(\omega)-D_0\sim c|\omega|^\alpha$; the paper itself notes the required decrease of $D_0$ with $L$ is only marginally confirmed.

Editorial extensions

If this is right

  • If $D_s^0\simeq D_e^0$ at large $W$, the Thouless time $\tau_{\rm Th}=L^2/D^0$ is controlled equally by spin and energy channels, so estimates of relaxation based only on spin diffusion miss half the story.
  • The failure of $R$ to drop below one, together with $R(L)$ increasing, implies that the finite-size systems studied are not in a localized phase, so an MBL transition must lie at larger $L$ or $W$.
  • The subdiffusive form $D(\omega)\simeq D_0+c|\omega|^\alpha$ with $\alpha<1$ implies the d.c. polarizability diverges, so the random-field chain is qualitatively different from a quasiperiodic chain, where $\alpha\gtrsim 1$.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the near equality $D_s^0\simeq D_e^0$ persists at larger $L$, then thermal and spin response are governed by the same local current; one testable consequence is that disorder-averaged thermal and spin imbalance decay should collapse onto the same time scale at strong disorder.
  • The log-normal sample-to-sample distribution of $D_0$ at $W\gtrsim 2$ suggests that disorder averages are dominated by unusually good conductors, so typical rather than average diffusion constants may better characterize the slow dynamics.
  • The subdiffusion scenario could be probed experimentally in cold-atom realizations by measuring the low-frequency tail of the response function: a diverging d.c. polarizability predicts a specific algebraic decay of the return probability, while localization would give an exponential cutoff.
  • The paper's resonant-island argument with effective exchange distance $d\propto W/\zeta$ suggests a further numerical test: extract the distribution of insulating island lengths from individual samples and check whether the log-normal tail width tracks the exponent $b\approx 2.5$.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 4 minor

Summary. The paper studies high-temperature spin and energy diffusion in the disordered XXZ Heisenberg chain with random local fields. It derives an Einstein/Kubo expression for the energy diffusivity De(ω) on the same footing as the spin diffusivity Ds(ω), computes per-sample random-matrix-theory markers and the Thouless level sensitivity R, and uses exact diagonalization (L≤18) and microcanonical Lanczos (L≤28) to obtain distributions and dynamical spectra of both diffusivities. The central claims are that at strong disorder W≳2 the two diffusion constants become essentially equal and decay as exp(−bW/J) with b≈2.5; that R remains above 1 and increases with L, incompatible with a simple Thouless localization criterion at reachable sizes; and that the dynamical diffusivity behaves as D(ω)≈D0+c|ω|^α with α<1 for random fields, indicating subdiffusive transport, whereas quasiperiodic fields yield α≈1.

Significance. If confirmed, the results would strengthen the Griffiths/subdiffusion picture over a genuine many-body-localization transition at numerically accessible sizes, and the energy-diffusion Einstein relation would be a lasting methodological contribution. The paper is also valuable for its per-sample RMT analysis, its explicit comparison between random and quasiperiodic fields, and its openly available data. However, the subdiffusive conclusion rests on power-law fits in a narrow low-frequency window and on a size dependence of D0 that the authors themselves describe as only marginally confirmed; the significance is therefore conditional on additional scaling and resolution checks.

major comments (4)
  1. [Section V, Fig. 7] The central subdiffusion claim is based on fits of Ds(ω)−D0s to c|ω|^α in the window 0<ω<0.05 for two random-field configurations at L=28. Because the MCLM resolution is δω∼10^-4 (Section IV) and D0s at W≳3.5 is itself of order 10^-4 (Fig. 3), the low-frequency end of the fit window is close to the resolution limit, and the fitted α could reflect the resolution cutoff and the finite-size d.c. plateau rather than an asymptotic low-frequency law. Please provide fits with a varying lower cutoff, results at several L for the same disorder samples, and a sample-averaged α with error bars; without this, α<1 is not established as a thermodynamic-limit property.
  2. [Section V, Fig. 5] The subdiffusion scenario requires D0s(L)→0, but Fig. 5 shows no systematic size reduction for W≤2 and only a weak trend for W≥3, and the text concedes that the decrease is only marginally confirmed. Since D0s is also subtracted as the baseline in the fits of Fig. 7, the size dependence of the baseline is load-bearing. Please quantify the trend (e.g., typical versus mean D0 versus 1/L with uncertainty estimates) or explicitly downgrade the claim to a conjecture supported by indirect evidence.
  3. [Section III, Fig. 2] The conclusion that R exceeds 1 and increases with L combines ED data for L≤18 (Nc=10, finite flux) with MCLM data for L≥20 (Nc=100, approximated Δe from Eq. (10)). This methodological and statistical discontinuity at L=20 could itself produce a rising trend in R(L); the authors should demonstrate continuity by evaluating R on overlapping system sizes with the same method and comparable Nc, or otherwise show that the increasing trend is not a numerical artifact.
  4. [Section V] Although the paper states that both spin and energy diffusivities show D(ω)≈D0+c|ω|^α, the α fits are shown only for spin (Fig. 7), while the energy spectra in Fig. 6 are not fitted. Given the claim that D0s and D0e become equal at strong disorder, direct low-frequency fits of De(ω) are needed to support the statement that energy transport is also subdiffusive.
minor comments (4)
  1. [Figure 4(c)] The caption and panel label refer to the energy diffusion CDF as D0s; this should read D0e.
  2. [Section V, text after Eq. (12)] An unresolved citation appears as '[46? ]'; please replace it with a complete reference.
  3. [Reference list] Reference [45] is cited as an arXiv preprint from 2024; if a journal version now exists, it should be cited instead or additionally.
  4. [General presentation] Several captions and sentences contain awkward word order, e.g., 'the inset displays also the comparison'; a careful language edit throughout would improve readability.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the diffusion constants and subdiffusive exponent are numerical outputs, not encoded in the model definitions or fits.

full rationale

No step in the paper's derivation chain reduces by definition to its own inputs. The spin and energy diffusivities are computed from Kubo-formula matrix-element sums (Eqs. 3 and 6) with static susceptibilities given by independent operator expectation values (Eqs. 4 and 7); the energy-diffusion Einstein relation is derived rather than assumed. The d.c. values D0_s and D0_e are numerical outputs, and the exponential dependence exp(-bW/J) is an empirical fit, not an input. The subdiffusion signature D(ω) - D0 ~ c|ω|^α is extracted by fitting numerical MCLM spectra in the 0 < ω < 0.05 window; the fit coefficients are not predetermined by any normalization or by the definition of D0. The comparison with quasiperiodic chains is a new calculation (Fig. 8), not a mere quotation of the authors' earlier result. The only self-citations, e.g., Ref. [32] for the resonant-island picture and Ref. [34] as a quasiperiodic reference, are used as interpretive context; the central claims rest on the present numerical data and on external references such as Refs. [17], [45], and [46]. The paper's admitted limitation that the decrease of D0 with L is only marginally confirmed (Section V and VI) is a finite-size statistical caveat, not evidence of circularity.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The main contributions rest on standard linear-response and numerical ED/MCLM techniques. The most fragile ingredient is the ad hoc frequency-window assumption used to extract the subdiffusive exponent α, together with the implicit assumption that L ≤ 28 data represent the thermodynamic limit.

free parameters (3)
  • b (exponential decay rate) = ≈2.5 (from fits in Fig. 3)
    Fitted to characterize D_0 ∝ exp(-bW/J) for W > 1.5; used in the comparison between random and quasiperiodic fields.
  • α (frequency exponent) = ≈0.5 at W≈2, approaching ~1 at larger W (Fig. 7c)
    Fitted in the window 0<ω<0.05 to support the subdiffusion scenario for random fields; the contrast with α≈1 for quasiperiodic fields is also fit-based.
  • c (prefactor in c|ω|^α) = not specified
    Additional fit parameter in D(ω)-D_0 = c|ω|^α, required to extract α.
assumptions (4)
  • standard math Kubo formula and Einstein relation connect d.c. diffusion to zero-frequency current autocorrelations (Eqs. 3 and 6).
    Invoked in Section II to express D_s and D_e in terms of current matrix elements; standard linear-response theory.
  • domain assumption Hydrodynamic limit q→0 is valid for the dynamical diffusivity D(ω) extracted from current correlations.
    Used to relate M_q(ω) to q^2 σ(ω)/χ^0; assumed to hold for the small-q response.
  • domain assumption The microcanonical Lanczos method at T→∞ with energy E≈0 is equivalent to the canonical Kubo formula for the current autocorrelation in the large-L limit.
    Central to the L=20-28 results; relies on the validity of MCLM with finite δω ≈ 1e-4.
  • ad hoc to paper The frequency window 0<ω<0.05 is in the asymptotic low-frequency regime where D(ω)-D_0 ~ c|ω|^α.
    The exponent α is extracted from this window; if the window is not asymptotic, the subdiffusion conclusion is not supported.

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Cite this review

Pith. "Pith review of Spin and energy diffusion vs. subdiffusion in disordered spin chains." pith.science (2026). https://pith.science/paper/F7X2L5FB

@misc{pith2026250415705,
  author       = {Pith},
  title        = {Pith review of: Spin and energy diffusion vs. subdiffusion in disordered spin chains},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/F7X2L5FB}},
  note         = {Machine review of arXiv:2504.15705}
}
read the original abstract

While the high-temperature spin diffusion in spin chains with random local fields has been the subject of numerous studies concerning the phenomenon of many-body localization (MBL), the energy diffusion in the same models has been much less explored. We demonstrate that energy diffusion is faster at weak random fields but becomes essentially equal at strong fields; hence, both diffusions determine the slowest relaxation time scale (Thouless time) in the system. Numerically reachable finite-size systems reveal the anomalously large distribution of diffusion constants with respect to actual field configurations. Despite the exponential-like dependence of diffusion on field strength, the results for sensitivity to twisted boundary conditions are incompatible with the Thouless criterion for localization and the presumed transition to MBL, at least for numerically reachable sizes. In contrast, we find indications of the scenario of subdiffusive transport, particularly in the dynamical diffusivity response.

Figures

Figures reproduced from arXiv: 2504.15705 by the authors.

Figure 2
Figure 2. Level sensitivity R: (a) vs. W for different L: for L = 14−18 obtained via direct ED, and for L = 20−28 via MCLM with approximated ∆e (see text for details), (b) the same averaged R vs. L for different W. The results for L ≤ 18 (L ≥ 20) were obtained as average over Nc = 10 (Nc = 100) random field configurations. pear in each sample quite simultaneously with the crossover at R ∼ 1. (c) While the sample-sample fluctu… view at source ↗
Figure 3
Figure 3. (a) Different presentations of the distribution of d.c. spin [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗
Figure 5
Figure 5. System size L dependence of spin diffusion D 0 s for W = 1, 2, 3. Shown are MCLM (ED) results for L ≥ 20 (L ≤ 18) and Nc = 3 different configurations. The dotted lines are guides to the eye, denoting the general trend with L. change between resonant sites is then given by |J eff l | ∝ J d 2 d|wl+1wl+2 · · · wl+d−1| ∼  J 2W ln W ζ d . (12) Notably, the scenario of such transport is qualitatively differ￾ent from the… view at source ↗
Figures from the paper (4 more)
Figure 4
Figure 4. Figure 4: Cumulative distribution function (CDF) for (a) d.c. spin [PITH_FULL_IMAGE:figures/full_fig_p005_4.png]
Figure 6
Figure 6. Figure 6: Dynamical (a) spin and (b) energy diffusivity [PITH_FULL_IMAGE:figures/full_fig_p006_6.png]
Figure 7
Figure 7. Figure 7: (a,b) Dynamical spin diffusivity Ds(ω) − D0 s for two ran￾dom field configurations with few W, calculated on L = 28 chain. Each panel represents a different wl configuration. The black dashed lines correspond to the fits to the c|ω| α function in the 0 < ω < 0.05 regio…
Figure 8
Figure 8. Figure 8: (a) Dynamical spin diffusivity Ds(ω), calculated via MCLM for for quasiperiodic system (L = 27). See text for details. (b) Frequency dependence of Ds(ω) − D0 s , together with fits to the c|ω| α function (black, dashed lines). The inset depicts α dependence on the (qua…

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Works this paper leans on

67 extracted references · 54 canonical work pages

  1. [1]

    P. W. Anderson, Absence of Diffusion in Certain Random Lat- tices, Phys. Rev. 109, 1492 (1958)

  2. [2]

    Abrahams, P

    E. Abrahams, P. W. Anderson, D. C. Licciardello, and T. V . Ra- makrishnan, Scaling theory of localization: absense of quantum diffusion in two dimensions, Phys. Rev. Lett. 42, 673 (1979)

  3. [3]

    Evers and A

    F. Evers and A. D. Mirlin, Anderson transitions, Rev. Mod. Phys. 80, 1355 (2008)

  4. [4]

    Kramer and A

    B. Kramer and A. MacKinnon, Localization: theory and exper- iment, Rep. Prog. Phys. 56, 1469 (1993)

  5. [5]

    Markos, Numerical analysis of the anderson localization, Acta Phys

    P. Markos, Numerical analysis of the anderson localization, Acta Phys. Slovaca 56, 561 (2006)

  6. [6]

    Basko, I

    D. Basko, I. Aleiner, and B. Altshuler, Metal–insulator transi- tion in a weakly interacting many-electron system with local- ized single-particle states, Ann. Phys. (N. Y .)321, 1126 (2006)

  7. [7]

    Oganesyan and D

    V . Oganesyan and D. A. Huse, Localization of interacting fermions at high temperature, Phys. Rev. B 75, 155111 (2007)

  8. [8]

    D. J. Luitz, N. Laflorencie, and F. Alet, Many-body localization edge in the random-field Heisenberg chain, Phys. Rev. B 91, 081103 (2015)

Show all 67 references
  1. [9]

    Serbyn and J

    M. Serbyn and J. E. Moore, Spectral statistics across the many- body localization transition, Phys. Rev. B 93, 041424 (2016)

  2. [10]

    ˇSuntajs, J

    J. ˇSuntajs, J. Bonˇca, T. Prosen, and L. Vidmar, Quantum chaos challenges many-body localization, Phys. Rev. E 102, 062144 (2020)

  3. [11]

    Sierant, D

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

  4. [12]

    ˇZnidariˇc, T

    M. ˇZnidariˇc, T. Prosen, and P. Prelovˇsek, Many-body localiza- tion in the Heisenberg XXZ magnet in a random field, Phys. Rev. B 77, 064426 (2008)

  5. [13]

    J. H. Bardarson, F. Pollmann, and J. E. Moore, Unbounded Growth of Entanglement in Models of Many-Body Localiza- tion, Phys. Rev. Lett. 109, 017202 (2012)

  6. [14]

    Serbyn, Z

    M. Serbyn, Z. Papi ´c, and D. A. Abanin, Criterion for Many- Body Localization-Delocalization Phase Transition, Phys. Rev. X 5, 041047 (2015)

  7. [15]

    T. C. Berkelbach and D. R. Reichman, Conductivity of disor- dered quantum lattice models at infinite temperature :, Phys. Rev. B 81, 224429 (2010)

  8. [16]

    O. S. Bari ˇsi´c and P. Prelov ˇsek, Conductivity in a disordered one-dimensional system of interacting fermions, Phys. Rev. B 82, 161106 (2010)

  9. [17]

    Agarwal, S

    K. Agarwal, S. Gopalakrishnan, M. Knap, M. M ¨uller, and E. Demler, Anomalous Diffusion and Griffiths Effects Near the Many-Body Localization Transition, Phys. Rev. Lett. 114, 160401 (2015)

  10. [18]

    Bar Lev, G

    Y . Bar Lev, G. Cohen, and D. R. Reichman, Absence of Diffu- sion in an Interacting System of Spinless Fermions on a One- Dimensional Disordered Lattice, Phys. Rev. Lett. 114, 100601 (2015)

  11. [19]

    Steinigeweg, J

    R. Steinigeweg, J. Herbrych, F. Pollmann, and W. Brenig, Scal- ing of the Optical Conductivity in the Transition from Thermal to Many-Body Localized Phases, Phys. Rev. B 94, 180401(R) (2016)

  12. [20]

    Prelov ˇsek, M

    P. Prelov ˇsek, M. Mierzejewski, O. Bari ˇsi´c, and J. Herbrych, Density correlations and transport in models of many-body lo- calization, Ann. Phys. (Berl.) 529, 1600362 (2017)

  13. [21]

    Pal and D

    A. Pal and D. A. Huse, Many-body localization phase transi- tion, Phys. Rev. B 82, 174411 (2010)

  14. [22]

    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, 127201 (2013)

  15. [23]

    D. A. Huse, R. Nandkishore, and V . Oganesyan, Phenomenol- ogy of fully many-body-localized systems, Phys. Rev. B 90, 174202 (2014)

  16. [24]

    D. J. Luitz, N. Laflorencie, and F. Alet, Extended slow dynam- ical regime prefiguring the many-body localization transition, Phys. Rev. B 93, 060201 (2016)

  17. [25]

    Mierzejewski, J

    M. Mierzejewski, J. Herbrych, and P. Prelov ˇsek, Universal dy- namics of density correlations at the transition to many-body localized state, Phys. Rev. B 94, 224207 (2016)

  18. [26]

    ˇSuntajs, J

    J. ˇSuntajs, J. Bon ˇca, T. Prosen, and L. Vidmar, Ergodicity breaking transition in finite disordered spin chains, Phys. Rev. B 102, 064207 (2020)

  19. [27]

    Sels and A

    D. Sels and A. Polkovnikov, Dynamical obstruction to local- ization in a disordered spin chain, Phys. Rev. E 104, 054105 (2021)

  20. [28]

    Vidmar, B

    L. Vidmar, B. Krajewski, J. Bon ˇca, and M. Mierzejewski, Phe- nomenology of Spectral Functions in Disordered Spin Chains at Infinite Temperature, Phys. Rev. Lett.127, 230603 (2021)

  21. [29]

    Krajewski, L

    B. Krajewski, L. Vidmar, J. Bon ˇca, and M. Mierzejewski, Restoring Ergodicity in a Strongly Disordered Interacting Chain, Phys. Rev. Lett. 129, 260601 (2022)

  22. [30]

    O. S. Bari ˇsi´c, J. Kokalj, I. Balog, and P. Prelovˇsek, Dynamical conductivity and its fluctuations along the crossover to many- body localization, Phys. Rev. B 94, 045126 (2016)

  23. [31]

    Prelov ˇsek, M

    P. Prelov ˇsek, M. Mierzejewski, J. Krsnik, and O. S. Bari ˇs´c, Many-body localization as a percolation phenomenon, Phys. Rev. B 103, 045139 (2021)

  24. [32]

    Herbrych, M

    J. Herbrych, M. Mierzejewski, and P. Prelov ˇsek, Relaxation at different length scales in models of many-body localization, Phys. Rev. B 105, L081105 (2022)

  25. [33]

    Krajewski, M

    B. Krajewski, M. Mierzejewski, and J. Bon ˇca, Modeling sample-to-sample fluctuations of the gap ratio in finite disor- dered spin chains, Phys. Rev. B 106, 014201 (2022)

  26. [34]

    Prelovˇsek, J

    P. Prelovˇsek, J. Herbrych, and M. Mierzejewski, Slow diffusion and Thouless localization criterion in modulated spin chains, Phys. Rev. B 108, 035106 (2023)

  27. [35]

    S. Iyer, V . Oganesyan, G. Refael, and D. A. Huse, Many-body localization in a quasiperiodic system, Phys. Rev. B87, 134202 (2013)

  28. [36]

    Bar Lev, D

    Y . Bar Lev, D. M. Kennes, C. Kl ¨ockner, D. R. Reichman, and C. Karrasch, Transport in quasiperiodic interacting systems: From superdiffusion to subdiffusion, EPL (Europhysics Letters) 119, 37003 (2017)

  29. [37]

    Khemani, D

    V . Khemani, D. N. Sheng, and D. A. Huse, Two Universality Classes for the Many-Body Localization Transition, Phys. Rev. Lett. 119, 075702 (2017)

  30. [38]

    Setiawan, D

    F. Setiawan, D. L. Deng, and J. H. Pixley, Transport properties across the many-body localization transition in quasiperiodic and random systems, Phys. Rev. B 96, 104205 (2017)

  31. [39]

    ˇZnidariˇc and M

    M. ˇZnidariˇc and M. Ljubotina, Interaction instability of local- ization in quasiperiodic systems, Proc. Natl. Acad. Sci. USA 115, 4595 (2018)

  32. [40]

    S. X. Zhang and H. Yao, Universal Properties of Many-Body Localization Transitions in Quasiperiodic Systems, Phys. Rev. Lett. 121, 206601 (2018)

  33. [41]

    A. S. Aramthottil, T. Chanda, P. Sierant, and J. Zakrzewski, Finite-size scaling analysis of the many-body localization tran- sition in quasiperiodic spin chains, Phys. Rev. B 104, 214201 (2021)

  34. [42]

    Sierant and J

    P. Sierant and J. Zakrzewski, Challenges to observation of 9 many-body localization, Phys. Rev. B 105, 224203 (2022)

  35. [43]

    Schreiber, S

    M. Schreiber, S. S. Hodgman, P. Bordia, H. P. L ¨uschen, M. H. Fischer, R. V osk, E. Altman, U. Schneider, and I. Bloch, Ob- servation of many-body localization of interacting fermions in a quasi-random optical lattice, Science 349, 842 (2015)

  36. [44]

    H. P. L ¨uschen, P. Bordia, S. Scherg, F. Alet, E. Altman, U. Schneider, and I. Bloch, Observation of Slow Dynamics near the Many-Body Localization Transition in One-Dimensional Quasiperiodic Systems, Phys. Rev. Lett. 119, 260401 (2017)

  37. [45]

    De Roeck, L

    W. De Roeck, L. Giacomin, F. Huveneers, and O. Prosniak, Ab- sence of Normal Heat Conduction in Strongly Disordered Inter- acting Quantum Chains, arXiv (2024), arXiv:2408.04338

  38. [46]

    Gopalakrishnan, K

    S. Gopalakrishnan, K. Agarwal, E. A. Demler, D. A. Huse, and M. Knap, Griffiths effects and slow dynamics in nearly many- body localized systems, Phys. Rev. B 93, 134206 (2016)

  39. [47]

    Jen ˇciˇc and P

    B. Jen ˇciˇc and P. Prelov ˇsek, Spin and thermal conductivity in classical disordered spin chain, Phys. Rev. B92, 134305 (2015)

  40. [48]

    J. J. Mendoza-Arenas, M. ˇZnidariˇc, V . K. Varma, J. Goold, S. R. Clark, and A. Scardicchio, Asymmetry in energy versus spin transport in certain interacting disordered systems, Phys. Rev. B 99, 094435 (2019)

  41. [49]

    V . K. Varma, A. Lerose, F. Pietracaprina, J. Goold, and A. Scardicchio, Energy diffusion in the ergodic phase of a many body localizable spin chain, J. Stat. Mech. Theor. Exp. 2017, 053101 (2017)

  42. [50]

    Schulz, S

    M. Schulz, S. R. Taylor, C. A. Hooley, and A. Scardicchio, Energy transport in a disordered spin chain with broken U(1) symmetry: Diffusion, subdiffusion, and many-body localiza- tion, Phys. Rev. B 98, 180201 (2018)

  43. [51]

    Serbyn, Z

    M. Serbyn, Z. Papi ´c, and D. A. Abanin, Thouless energy and multifractality across the many-body localization transition, Phys. Rev. B 96, 104201 (2017)

  44. [52]

    J. T. Edwards and D. J. Thouless, Numerical studies of localiza- tion in structurally disordered systems, J. Phys. C: Solid State Phys. 5, 807 (1972)

  45. [53]

    Sierant, M

    P. Sierant, M. Lewenstein, A. Scardicchio, L. Vidmar, and J. Zakrzewski, Many-Body Localization in the Age of Classical Computing, Rep. Prog. Phys. 88, 026502 (2025)

  46. [54]

    Wilkinson, Diffusion and dissipation in complex quantum systems, Phys

    M. Wilkinson, Diffusion and dissipation in complex quantum systems, Phys. Rev. A 41, 4645 (1990)

  47. [55]

    D’Alessio, Y

    L. D’Alessio, Y . Kafri, A. Polkovnikov, and M. Rigol, From quantum chaos and eigenstate thermalization to statistical me- chanics and thermodynamics, Adv. Phys. 65, 239 (2016)

  48. [56]

    Mori, Transport, collective motion, and Brownian motion, Prog

    H. Mori, Transport, collective motion, and Brownian motion, Prog. Theor. Phys. 33, 423 (1965)

  49. [57]

    Forster, Hydrodynamic Fluctuations, Broken Symmetry and Correlation Functions (Taylor - Francis Group, CRC Press, 1975)

    D. Forster, Hydrodynamic Fluctuations, Broken Symmetry and Correlation Functions (Taylor - Francis Group, CRC Press, 1975)

  50. [58]

    Bon ˇca and J

    J. Bon ˇca and J. Jakli ˇc, Spin diffusion of the t-J model, Phys. Rev. B 51, 16083 (1995)

  51. [59]

    Karahalios, A

    A. Karahalios, A. Metavitsiadis, X. Zotos, A. Gorczyca, and P. Prelovˇsek, Finite-temperature transport in disordered Heisen- berg chains, Phys. Rev. B 79, 024425 (2009)

  52. [60]

    Kohn, Theory of the Insulating State, Phys

    W. Kohn, Theory of the Insulating State, Phys. Rev. 133, A171 (1964)

  53. [61]

    Castella and X

    H. Castella and X. Zotos, Finite-temperature mobility of a par- ticle coupled to a fermionic environment, Phys. Rev. B54, 4375 (1996)

  54. [62]

    M. Long, P. Prelov ˇsek, S. El Shawish, J. Karadamoglou, and X. Zotos, Finite-temperature dynamical correlations using the microcanonical ensemble and the Lanczos algorithm, Phys. Rev. B 68, 235106 (2003)

  55. [63]

    Prelovˇsek and J

    P. Prelovˇsek and J. Bonˇca, Ground State and Finite Temperature Lanczos Methods, in Strongly Correlated Systems - Numerical Methods, edited by A. Avella and F. Mancini (Springer, Berlin, 2013)

  56. [64]

    Gopalakrishnan, M

    S. Gopalakrishnan, M. M ¨uller, V . Khemani, M. Knap, E. Dem- ler, and D. A. Huse, Low-frequency conductivity in many-body localized systems, Phys. Rev. B 92, 104202 (2015)

  57. [65]

    Prelovˇsek and J

    P. Prelovˇsek and J. Herbrych, Self-consistent approach to many- body localization and subdiffusion, Phys. Rev. B 96, 035130 (2017)

  58. [66]

    A. C. Potter, R. Vasseur, and S. A. Parameswaran, Universal properties of many-body delocalization transitions, Phys. Rev. X 5, 031033 (2015)

  59. [67]

    All data discussed in this paper are available at https:// github.com/jacekherbrych/DataRepository

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