MajumdarGhosh — model index
The Majumdar-Ghosh chain — the $J_2 = J_1/2$ frustrated Heisenberg chain with an exact, doubly-degenerate nearest-neighbour dimerized ground state.
\[H = J_1\sum_i \mathbf{S}_i \cdot \mathbf{S}_{i+1} + J_2\sum_i \mathbf{S}_i \cdot \mathbf{S}_{i+2}, \qquad J_2 = J_1/2\]
Generated by docs/atlas/generate.jl — a pure VIEW over the *_registry.jl claims + the static test/INVENTORY.jsonl AST scan. No test is executed and no src is run; test/INVENTORY.jsonl is regenerated in-place (idempotently) from that static scan; fetch/@register untouched. Assurance labels are PROVISIONAL: residuals / confidence are not shown yet (RES not wired). Badges reflect the committed test AST, not the latest CI run — a hub can read green while its @test is red between regenerations. @sweep = a graceful regime-resolution gap, not card omission.
All (Quantity, BC) hubs src claims for MajumdarGhosh. Cells link to the per-hub card; — = not yet implemented at that BC. The shape of the matrix is the gap visualisation: empty cells are where physics could be added next.
Convention
| Field | Value |
|---|---|
| Hamiltonian | Spin S (this file) |
| Observable | Spin S (QAtlas-wide spin convention; see docs/src/conventions.md) |
Coverage
| Level | Count |
|---|---|
| 🟣 universality-corroborated | 0 |
| 🟢 corroborated-at-p | 2 |
| 🔵 coherent | 0 |
| ⚪ cited-only | 2 |
| 🟠 uncorroborated-but-feasible | 0 |
| total claimed hubs | 4 |
Methods (from @register, derived): analytic, dmrg_reference
Quantity × BC matrix
| Quantity | PBC | Infinite |
|---|---|---|
GroundStateEnergyDensity | 🟢 hub | 🟢 hub |
MassGap | — | ⚪ hub |
SpinGap | — | ⚪ hub |
References
Papers cited by this model's @register cards. The full numbered list is on the Reference List.
- [116]
- S. Eggert. Numerical evidence for multiplicative logarithmic corrections from marginal operators. Physical Review B 54, R9612–R9615 (1996).
- [114]
- C. K. Majumdar and D. K. Ghosh. On Next-Nearest-Neighbor Interaction in Linear Chain. I. Journal of Mathematical Physics 10, 1388–1398 (1969).
- [73]
- B. Sriram Shastry and B. Sutherland. Exact ground state of a quantum mechanical antiferromagnet. Physica B+C 108, 1069–1070 (1981).
- [115]
- S. R. White and I. Affleck. Dimerization and incommensurate spiral spin correlations in the zigzag spin chain: Analogies to the Kondo lattice. Physical Review B 54, 9862–9869 (1996).