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J1-J2 square 10x10, J2 = 0.5

J1J2/square_100_P_0.5

Record

-0.4976939(2) E/N (S.S)

CNN-MPS (h,D,l)=(32,20,20), Marshall sign transformation

Fan et al. (2026) · lowest eligible strict variational bound (rules §6)

The Hamiltonian

H = ∑⟨ij⟩ σi·σj + J2⟨⟨ij⟩⟩ σi·σj

J1 = 1, J2 = 0.5, nearest and next-nearest neighbours, written with Pauli matrices.

lattice
square
sites
100
boundary
periodic
J2
0.5
energies
15

Stored as a total energy in the convention of VarBench; quoted here as E/N (S.S), which is what the papers report (how the conversion works).

Every published energy

Grouped by what the number is. Ranking happens only inside the first group.

Strict variational upper bounds (14)

The record is the lowest eligible energy in this group, and only this group.

E/N (S.S)σVar(E)V-score methodsourceyear
-0.49782(3) 3.0e-5 n/a n/a Holographic Quantum Transformer (HQT), zero-shot 8x8->10x10 transfer
flagged: energy-variance-inconsistent peer reviewed
Guo et al. (2026) 2026
-0.4976939(2)record 2.0e-7 n/a n/a CNN-MPS (h,D,l)=(32,20,20), Marshall sign transformation
preprint
Fan et al. (2026) 2026
-0.4976923(2) 2.0e-7 n/a n/a T-MPS
preprint
Fan et al. (2026) 2026
-0.4976921(4) 4.0e-7 n/a n/a ResNet2 (64 conv layers, >1e6 params), MinSR
peer reviewed
Chen & Heyl (2023) 2023
-0.4976764(7) 7.0e-7 n/a n/a Convolutional transformer wave function (CTWF)
preprint
Chen et al. (2025) 2025
-0.497634(1) 1.0e-6 n/a n/a fViT (vision transformer, 2.7e5 params)
quoted from another paper peer reviewed
Nutakki et al. (2025) 2025
-0.497629(1) 1.1e-6 7.90e-1 2.0e-3 RBM+PP with momentum (K=0), spin-parity (even S), and point-group (A1) projections, 16 hidden units Nomura & Imada (2021) 2021
-0.497583(6) 6.0e-6 n/a n/a ConvNext (6,3,3)[2,2], 2.6e5 params
peer reviewed
Nutakki et al. (2025) 2025
-0.49560(4) 4.3e-5 4.67e+0 1.2e-2 RNN + translational symmetry
VarBench reference run
run script, no paper cited n/a
-0.495393(8) 7.5e-6 1.62e+0 4.1e-3 RNN
VarBench reference run
run script, no paper cited n/a
-0.49515(2) 2.2e-5 1.16e+1 3.0e-2 VMC with projected BCS (Z2 spin liquid)
VarBench reference run
run script, no paper cited n/a
-0.4913983 n/a 1.67e+1 4.3e-2 DMRG (bond dimension = 1024)
VarBench reference run
run script, no paper cited n/a
-0.47700(2) 2.1e-5 7.16e+1 2.0e-1 RBM (alpha = 1)
VarBench reference run
run script, no paper cited n/a
-0.47390(2) 2.1e-5 7.17e+1 2.0e-1 Jastrow baseline
VarBench reference run
run script, no paper cited n/a

Extrapolations (1)

Zero-variance, bond-dimension or Trotter-error extrapolations. Not a bound: no ansatz ever reached the number, so it cannot hold the record.

E/N (S.S)σVar(E)V-score methodsourceyear
-0.497715(9) 9.0e-6 n/a n/a ResNet2 MinSR, zero-variance extrapolation
peer reviewed
Chen & Heyl (2023) 2023

Flagged rows

A flag withholds the record and nothing else: the row stays listed, in rank order. Rules §10 is how a flag is lifted or upheld.

energy-variance-inconsistent — Holographic Quantum Transformer (HQT), zero-shot 8x8->10x10..., -0.49782(3)

Finding. Claimed 1.3e-4 below the best variational energy (CNN-MPS) while the paper itself calls the number 'statistically consistent with the variational state of the art' - it is lower by ~4x its own stated error bar, so if real it is an unclaimed record. There is NO exact reference at 10x10 (ED reaches ~6x6 for this model), so this is a contested record claim, not a proven error.

Diagnosis. The reported energy is inconsistent with the paper's OWN reported variance. At 8x8 the claimed E/N = -0.5001 beats RBM+PP's -0.4989635 while the reported variance (sigma^2 = 1.4e-3 per site, S.S units) gives a V-score of 5.6e-3 against RBM+PP's 9.81e-4 - 5.7x worse. Energy and variance move together - a state further from an eigenstate cannot be lower in energy - so by the V-score calibration this energy should be ~1.2e-3 higher than claimed.

Ruled out. NOT 'below the exact ground state'. There is no exact reference at 8x8 or 10x10: ED for this model reaches about 6x6, and the paper correctly uses 6x6 ED (-0.5038) as its only exact anchor. Chen & Heyl's -0.497715(9) is a zero-variance extrapolation, not a bound, so a lower variational energy would only mean the extrapolation carries systematic error. The sigma^2 is per site, so the V-score is 5.6e-3 and not a range. Separately, the paper is internally inconsistent about it: Table 1 gives sigma^2 = 1.4e-3 for the 8x8 run while the J2 scan lists 0.0034 at J2 = 0.50, which would make the V-score 1.4e-2 and the contradiction larger. No variance is reported at 10x10 at all, so that row's flag rests only on it being an unclaimed record.

Evidence. arXiv:2607.00398 Tables 1-3; V-scores recomputed from this instance's own rows.

How these numbers were read

Rows added after the VarBench import record where the number came from.

-0.49782(3) — Holographic Quantum Transformer (HQT), zero-shot 8x8->10x10...

Checked 2026-09-13 · arXiv HTML parsed locally, no LLM transcription

Reported as. -0.49782 (+/- 0.00003) per site in S.S units

Abstract: "This zero-shot protocol yields an energy of E/N = -0.49782(3), statistically consistent with the variational state of the art". It is not consistent: it is 1.3e-4 BELOW the best variational energy (CNN-MPS -0.4976939(2)) and 1.05e-4 below the zero-variance extrapolated ground state -0.497715(9), i.e. below the ground state itself, which no variational energy can be. See the defect flag.

-0.497715(9) — ResNet2 MinSR, zero-variance extrapolation

Checked 2026-09-10 · source text/table parsed locally (arXiv HTML or pypdf), no LLM transcription

Reported as. -0.497715 (+/- 0.000009) per site in S.S units

PDF text: "estimate the ground-state energy E_GS/N = -0.497715(9) by zero-variance extrapolation". NOT a variational bound.

-0.4976939(2) — CNN-MPS (h,D,l)=(32,20,20), Marshall sign transformation

Checked 2026-09-13 · arXiv HTML parsed locally, no LLM transcription

Reported as. -0.4976939 (+/- 2e-7) per site in S.S units

Read from Table 1 of arXiv:2603.14425 (square-lattice J1-J2 at J2/J1=0.5, PBC, E per site in S.S units), parsed from the arXiv HTML. Claim: "the best energy obtained by CNN-MPS is -0.4976939(2) ... which is lower than the best previously reported result". Supersedes Chen & Heyl -0.4976921(4) as the record for this instance.

-0.4976923(2) — T-MPS

Checked 2026-09-13 · arXiv HTML parsed locally, no LLM transcription

Reported as. -0.4976923 (+/- 2e-7) per site in S.S units

Read from Table 1 of arXiv:2603.14425 (square-lattice J1-J2 at J2/J1=0.5, PBC, E per site in S.S units), parsed from the arXiv HTML.

-0.4976921(4) — ResNet2 (64 conv layers, >1e6 params), MinSR

Checked 2026-09-10 · source text/table parsed locally (arXiv HTML or pypdf), no LLM transcription

Reported as. -0.4976921 (+/- 4e-7) per site in S.S units

PDF text: "to attain the best variational energy E/N = -0.4976921(4)"

-0.4976764(7) — Convolutional transformer wave function (CTWF)

Checked 2026-09-13 · arXiv HTML parsed locally, no LLM transcription

Reported as. -0.4976764 (+/- 7e-7) per site in S.S units

Read from Table 1 of arXiv:2603.14425 (square-lattice J1-J2 at J2/J1=0.5, PBC, E per site in S.S units), parsed from the arXiv HTML. Cross-checked against the CTWF paper's own text.

-0.497634(1) — fViT (vision transformer, 2.7e5 params)

Checked 2026-09-10 · source text/table parsed locally (arXiv HTML or pypdf), no LLM transcription

Reported as. -0.497634 (+/- 0.000001) per site in S.S units

Read from Table 1 of the arXiv HTML of 2505.03466; primary source not checked.

-0.497583(6) — ConvNext (6,3,3)[2,2], 2.6e5 params

Checked 2026-09-10 · source text/table parsed locally (arXiv HTML or pypdf), no LLM transcription

Reported as. -0.497583 (+/- 0.000006) per site in S.S units

Table 1 of arXiv:2505.03466, their own result. Paper states L=10, PBC, S.S per site.

Coverage

Newest published number here: 2026. 8 rows added from the 2026-09 literature sweep, on top of the VarBench snapshot of 2024-10-22.

This instance as data

JSON · source file on GitHub · open an issue about this instance