Quantum Models

Quantum many-body and single-particle models with exact or rigorously verifiable solutions.

Contents

• Transverse-Field Ising Model (TFIM) – free-fermion solution via Jordan–Wigner, BdG spectrum, thermal observables, entanglement entropy
• Heisenberg Chain – spin-1/2 AFM chain, dimer and 4-site exact spectra, Bethe ansatz ground-state energy density
• Tight-Binding Models – nearest-neighbor hopping on 8 lattice topologies, with closed-form Bloch spectra and a generic builder
• Kitaev1D Wire – 1D p-wave Majorana wire (Kitaev 2001), Pfaffian Z_2 topological invariant, OBC Majorana edge modes (distinct from the 2D KitaevHoneycomb spin model)
• Hubbard1D Chain – 1D Hubbard model, Lieb-Wu Bethe ansatz half-filling closed forms (E_0/N, charge gap, spin gap)