fastdla.generators.heisenberg_hva.xxz_hva_generators

fastdla.generators.heisenberg_hva.xxz_hva_generators(num_spins, subspace_controllable=True)

Return the generators of the XXZ model HVA.

The definition of the generators follows Larocca et al. Quantum 6 (2022):

\[\begin{split}\mathcal{G}_{\mathrm{XXZ}_U} & = \left\{ \sum_{n \mathrm{even}} -i (X_n X_{n+1} + Y_n Y_{n+1}), \sum_{n \mathrm{odd}} -i (X_n X_{n+1} + Y_n Y_{n+1}), \sum_{n \mathrm{even}} -i Z_n Z_{n+1}, \sum_{n \mathrm{odd}} -i Z_n Z_{n+1} \right\} \\ \mathcal{G}_{\mathrm{XXZ}} & = \mathcal{G}_{\mathrm{XXZ}_U} \cup \{-i (Z_0 + Z_{N-1})\}.\end{split}\]

The generators commute with magnetization

\[M = \sum_{n=0}^{N-1} Z_n\]

and are symmetric under parity

\[P: A_n \mapsto A_{N-1-n}.\]
Return type:

SparsePauliSumArray