pith. sign in

arxiv: 2606.17933 · v1 · pith:ASWZJIZ7new · submitted 2026-06-16 · ❄️ cond-mat.str-el

Three-dimensional repulsive Hubbard model

Pith reviewed 2026-06-26 22:44 UTC · model grok-4.3

classification ❄️ cond-mat.str-el
keywords repulsive Hubbard modelthree-dimensional latticeantiferromagnetic phase boundaryMott transitionstrong-coupling diagram techniqueNeel temperaturecritical exponent
0
0 comments X

The pith

The three-dimensional repulsive Hubbard model at half filling has its paramagnetic-antiferromagnetic boundary determined between 4t and 12t with a Mott transition at approximately 9t.

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

The paper applies the strong-coupling diagram technique to the three-dimensional repulsive Hubbard model. It determines the boundary separating paramagnetic and antiferromagnetic states at half-filling for Hubbard repulsion values from 4t to 12t. Along this boundary the density of states reveals a Mott transition near U=9t. The work also examines how the Neel temperature depends on electron concentration for U=4t and U=12t and extracts a magnetic critical exponent of approximately 1.4 at strong coupling.

Core claim

Using the strong-coupling diagram technique the boundary between paramagnetic and antiferromagnetic states is determined for 4t ≤ U ≤ 12t at half-filling. The density of states along this boundary demonstrates the Mott transition at U ≈ 9t. For U = 12t the magnetic critical exponent γ ≈ 1.4 which is close to the value in the Heisenberg model.

What carries the argument

The strong-coupling diagram technique, which expands in the hopping integral and sums selected diagram classes to obtain Green's functions and magnetic susceptibilities.

Load-bearing premise

The strong-coupling diagram technique remains quantitatively reliable across the full range 4t ≤ U ≤ 12t without uncontrolled approximations that would shift the reported boundary or the location of the Mott transition.

What would settle it

Direct comparison of the reported Mott transition location near U=9t or the Neel temperature versus concentration curves with quantum Monte Carlo simulations on the same three-dimensional Hubbard model parameters would confirm or refute the results.

read the original abstract

The three-dimensional repulsive Hubbard model is investigated using the strong-coupling diagram technique. For half-filling, the boundary between paramagnetic and antiferromagnetic states is determined for the range of the Hubbard repulsion $4t\leq U\leq12t$, where $t$ is the hopping integral between neighboring sites. Along this boundary, the density of states is calculated, and it demonstrates the Mott transition at $U\approx9t$. For $U\geq6t$ and half-filling, the density of states has the shape inherent in the strong electron repulsion, while for $U=4t$, its shape points to weak coupling. The dependence of the N\'eel temperature $T_{\rm N}$ on the electron concentration $\bar{n}$ is investigated for the cases $U=4t$ and $12t$. In the former case, $T_{\rm N}$ decreases monotonously with $\bar{n}$, while in the latter case, there is a plateau in the dependence near $\bar{n}=0.87$. The plateau is connected to a reconstruction of the density of states caused by an effective weakening of electron coupling due to electron depopulation. For $U=12t$ and half-filling, the magnetic critical exponent $\gamma\approx1.4$, which is close to the value in the Heisenberg model. Some features resembling the first-order phase transition, revealing themselves in a finite crystal, are discussed.

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

1 major / 0 minor

Summary. The manuscript applies the strong-coupling diagram technique to the three-dimensional repulsive Hubbard model on the cubic lattice. At half filling it determines the paramagnetic-antiferromagnetic phase boundary for 4t ≤ U ≤ 12t, locates a Mott transition at U ≈ 9t from the density of states, examines the Néel temperature versus filling for U = 4t and U = 12t (reporting a plateau near n̄ = 0.87 for U = 12t), and extracts the magnetic critical exponent γ ≈ 1.4 at U = 12t.

Significance. If the strong-coupling diagram technique remains quantitatively controlled over the full range, the results would provide concrete information on the doping dependence of magnetic order and the location of the Mott transition in the 3D Hubbard model, including a non-monotonic TN(n) feature and an exponent close to the Heisenberg value.

major comments (1)
  1. [Abstract] The central claims—the PM-AF boundary for 4t ≤ U ≤ 12t, the Mott transition at U ≈ 9t, and γ ≈ 1.4—all rest on the strong-coupling diagram technique. At U = 4t the abstract itself states that the DOS shape indicates weak coupling, yet the expansion parameter t/U = 0.25 is not small; no convergence checks with higher-order diagrams, error estimates, or direct comparisons to QMC or DMFT on the same lattice are supplied to demonstrate that uncontrolled terms do not shift the reported boundary or transition point.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful reading and the constructive comment on our manuscript. We address the concern point by point below.

read point-by-point responses
  1. Referee: [Abstract] The central claims—the PM-AF boundary for 4t ≤ U ≤ 12t, the Mott transition at U ≈ 9t, and γ ≈ 1.4—all rest on the strong-coupling diagram technique. At U = 4t the abstract itself states that the DOS shape indicates weak coupling, yet the expansion parameter t/U = 0.25 is not small; no convergence checks with higher-order diagrams, error estimates, or direct comparisons to QMC or DMFT on the same lattice are supplied to demonstrate that uncontrolled terms do not shift the reported boundary or transition point.

    Authors: We agree that t/U = 0.25 is not a small parameter and that the manuscript already notes the weak-coupling character of the DOS at U = 4t. The strong-coupling diagram technique is applied uniformly over 4t ≤ U ≤ 12t to obtain a consistent description of the phase boundary and related quantities. No higher-order diagram calculations, quantitative error estimates, or direct QMC/DMFT benchmarks on the cubic lattice were performed in this study. In the revised manuscript we will add an explicit paragraph in the discussion section clarifying the expected range of validity of the expansion and the limitations at the smallest U values considered. revision: partial

Circularity Check

0 steps flagged

No circularity: results are direct outputs of diagrammatic calculation

full rationale

The paper applies the strong-coupling diagram technique to compute the PM-AF boundary for 4t≤U≤12t, the Mott transition location from DOS, TN(n) dependence, and the critical exponent γ≈1.4. These quantities are generated as outputs of the expansion rather than being fitted inputs, self-defined, or reduced to prior self-citations by construction. No equations or steps in the provided text equate a reported prediction to a parameter fit or to an unverified self-citation chain. The derivation remains self-contained against external benchmarks such as QMC or DMFT comparisons (even if those are not shown here).

Axiom & Free-Parameter Ledger

0 free parameters · 0 axioms · 0 invented entities

Abstract supplies no explicit list of free parameters, axioms, or invented entities; the technique itself is treated as given.

pith-pipeline@v0.9.1-grok · 5772 in / 1187 out tokens · 30571 ms · 2026-06-26T22:44:04.111893+00:00 · methodology

discussion (0)

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

Reference graph

Works this paper leans on

28 extracted references · 25 canonical work pages

  1. [1]

    Hirsch, Phys

    J.E. Hirsch, Phys. Rev. B35, 1851 (1987). https://doi.org/10.1103/PhysRevB.35.1851

  2. [2]

    Scalettar, D.J

    R.T. Scalettar, D.J. Scalapino, R.L. Sugar, D. Toussaint, Phys. Rev. B39, 4711 (1989). https://doi.org/10.1103/PhysRevB.39.4711

  3. [3]

    Staudt, M

    R. Staudt, M. Dzierzawa, A. Muramatsu, Eur. Phys. J. B17, 411 (2000). https://doi.org/10.1007/s100510070120

  4. [4]

    Jarrell, Phys

    M. Jarrell, Phys. Rev. Lett.69, 168 (1992). https://doi.org/10.1103/PhysRevLett.69.168

  5. [5]

    Ulmke, V

    M. Ulmke, V. Janiˇ s, D. Vollhardt, Phys. Rev. B51, 10411 (1995). https://doi.org/10.1103/PhysRevB.51.10411

  6. [6]

    P.R.C. Kent, M. Jarrell, T.A. Maier, T. Pruschke, Phys. Rev. B72, 060411 (2005). https://doi.org/10.1103/PhysRevB.72.060411

  7. [7]

    Rohringer, A

    G. Rohringer, A. Toschi, A. Katanin, K. Held, Phys. Rev. Lett.107, 256402 (2011). https://doi.org/10.1103/PhysRevLett.107.256402

  8. [8]

    Hirschmeier, H

    D. Hirschmeier, H. Hafermann, E. Gull, A.I. Lichtenstein, A.E. Antipov, Phys. Rev. B92, 144409 (2015). https://doi.org/10.1103/PhysRevB.92.144409

  9. [9]

    Kozik, E

    E. Kozik, E. Burovski, V.W. Scarola, M. Troyer, Phys. Rev. B87, 205102 (2013). https://doi.org/10.1103/PhysRevB.87.205102

  10. [10]

    Vladimir, V.A

    M.I. Vladimir, V.A. Moskalenko, Theor. Math. Phys.82, 301 (1990). https://doi.org/10.1007/BF01029224

  11. [11]

    Metzner, Phys

    W. Metzner, Phys. Rev. B43, 8549 (1991). https://doi.org/10.1103/PhysRevB.43.8549

  12. [12]

    Pairault , author D

    S. Pairault, D. S´ en´ echal, A.-M.S. Tremblay, Eur. Phys. J. B16, 85 (2000). https://doi.org/10.1007/s100510070253

  13. [13]

    Sherman, J

    A. Sherman, J. Phys.: Condens. Matter30, 195601 (2018). https://doi.org/10.1088/1361-648X/aaba0e

  14. [14]

    Moukouri, S

    S. Moukouri, S. Allen, F. Lemay, B. Kyung, D. Poulin, Y.M. Vilk, A.-M.S. Trem- blay, Phys. Rev. B61, 7887 (2000). https://doi.org/10.1103/PhysRevB.61.7887

  15. [15]

    Rushbrooke, G.A

    G.S. Rushbrooke, G.A. Baker, P.J Wood, inPhase Transitions and Critical Phenomena, edited by C. Domb, M.S. Green (Academic Press, New York, 1974). 16

  16. [16]

    Sandvik, Phys

    A.W. Sandvik, Phys. Rev. Lett.80, 5196 (1998). https://doi.org/10.1103/PhysRevLett.80.5196

  17. [17]

    C. Holm, W. Janke, Phys. Rev. B48, 936 (1993). https://doi.org/10.1103/PhysRevB.48.936

  18. [18]

    R. Kubo, J. Phys. Soc. Jpn.17, 1100 (1962). https://doi.org/10.1143/JPSJ.17.1100

  19. [19]

    Abrikosov, L.P

    A.A. Abrikosov, L.P. Gor’kov, I.E. Dzyaloshinskii,Methods of Quantum Field Theory in Statistical Physics(Pergamon Press, New York, 1965)

  20. [20]

    Sherman, J

    A. Sherman, J. Phys. Soc. Jpn.90, 104707 (2021). https://doi.org/10.7566/JPSJ.90.104707

  21. [21]

    Sherman, J

    A. Sherman, J. Low Temp. Phys.216, 800 (2024). https://doi.org/10.1007/s10909-024-03194-y

  22. [22]

    Sherman, Eur

    A. Sherman, Eur. Phys. J. B93, 168 (2020). https://doi.org/10.1140/epjb/e2020- 10221-4

  23. [25]

    Sherman, Phys

    A. Sherman, Phys. Scr.95, 095804 (2020). https://doi.org/10.1088/1402- 4896/aba923

  24. [26]

    Hasenfratz, Eur

    P. Hasenfratz, Eur. Phys. J. B13, 11 (2000). https://doi.org/10.1007/s100510050003

  25. [27]

    Press, S.A

    W.H. Press, S.A. Teukolsky, W.T. Vetterling, B.P. Flannery,Numerical Recipes in Fortran(Cambridge University Press, Cambridge, 1995), chapter 18

  26. [28]

    Jarrell \ and\ author J

    M. Jarrell, J.E. Gubernatis, Phys. Rept.269, 133 (1996). https://doi.org/10.1016/0370-1573(95)00074-7

  27. [29]

    Habershon, B.J

    S. Habershon, B.J. Braams, D.E. Manolopoulos, J. Chem. Phys.127, 174108 (2007). https://doi.org/10.1063/1.2786451

  28. [30]

    Slater, Phys

    J.C. Slater, Phys. Rev.82, 538 (1951). https://doi.org/10.1103/PhysRev.82.538 17