quimb.tensor.tn2dinf

Infinite, translation-invariant 2D tensor networks defined by a unit cell, e.g. infinite PEPS and their imaginary-time simple update.

Some notable definitions and conventions of terms used in this subpackage:

  • “site”: a concrete (cell, site_type) pair defining a location site in the infinite lattice.

  • “cell”: (dx, dy) integer unit-cell translation (not a position).

  • “site_type”: label of a site within the unit cell, all sites with the same site_type share data.

  • “bond_type”: a bond’s translation class, canonicalized with the first endpoint anchored at cell (0, 0) and the pair sorted.

  • “bond index”: the concrete index name on one specific translated bond.

  • “canonical”: the (0, 0) anchored representative keying a translation class.

  • “fragment”: the finite materialized TN patch standing in for the infinite network, that operations act on and are synced from.

  • “shared_tensors” / “shared_indices”: the set of tensors or indices in the fragment sharing the same site_type or bond_type, respectively.

  • “position”: the cartesian coordinate of a site, defined by the unit cell’s basis and the site_type’s fractional offset within the unit cell.

Submodules