• full name: tenpy.models.spins_nnn

  • parent module: tenpy.models

  • type: module


Inheritance diagram of tenpy.models.spins_nnn


Spin-S sites coupled by (next-)nearest neighbor interactions on a GroupedSite.


Spin-S sites coupled by next-nearest neighbor interactions.

Module description

Next-Nearest-neighbor spin-S models.

Uniform lattice of spin-S sites, coupled by next-nearest-neighbor interactions. We have two variants implementing the same hamiltonian. The SpinChainNNN uses the GroupedSite to keep it a NearestNeighborModel suitable for TEBD, while the SpinChainNNN2 just involves longer-range couplings in the MPO. The latter is preferable for pure DMRG calculations and avoids having to add each of the short range couplings twice for the grouped sites.

Note that you can also get a NearestNeighborModel for TEBD from the latter by using group_sites() and from_MPOModel(). An example for such a case is given in the file examples/c_tebd.py.