J1-J2-J3 and J1-J2-lambda Heisenberg Model

from 2x1 to 4x2 unit cell (PyTorch)

J1-J2 model defined on iPEPS with extended unit cell using dense PyTorch tensors.

from 2x1 to 4x2 unit cell (dense YAST)

J1-J2 model defined on ipeps.ipeps_abelian.IPEPS_ABELIAN with extended unit cell

This implementation of SU(2)-symmetric J1-J2 model works with dense YAST tensors. In particular, the physical reduced density matrices, Hamiltonian terms, observables, etc. are dense YAST tensors. As such, their indices have signature.

Note

The underlying iPEPS wavefunction can make use of explicit internal symmetry and thus block-sparse tensors. After physical reduced density matrices are built from such iPEPS and its environment, they are converted to dense form (keeping signature information).

1x1 C4v (PyTorch)

Single-site C4v symmetric IPEPS_C4V supports J1-J2-J3 model and J1-J2-lambda model. This implementation works with dense PyTorch tensors.

1x1 C4v (dense YAST)

Single-site C4v symmetric ipeps.ipeps_abelian_c4v.IPEPS_ABELIAN_C4V supports J1-J2 model.

This implementation of SU(2)-symmetric J1-J2 model works with dense YAST tensors. In particular, the physical reduced density matrices, Hamiltonian terms, observables, etc. are dense YAST tensors. As such, their indices have signature.

Note

The underlying iPEPS wavefunction can make use of explicit internal symmetry and thus block-sparse tensors. After physical reduced density matrices are built from such iPEPS and its environment, they are converted to dense form (keeping signature information).