OnsiteTerms

full name: tenpy.networks.terms.OnsiteTerms
parent module: tenpy.networks.terms
type: class

Inheritance Diagram

Methods

`OnsiteTerms.__init__`(L)
`OnsiteTerms.add_onsite_term`(strength, i, op)	Add a onsite term on a given MPS site.
`OnsiteTerms.add_to_graph`(graph)	Add terms from `onsite_terms` to an MPOGraph.
`OnsiteTerms.add_to_nn_bond_Arrays`(H_bond, ...)	Add `self.onsite_terms` into nearest-neighbor bond arrays.
`OnsiteTerms.from_hdf5`(hdf5_loader, h5gr, subpath)	Load instance from a HDF5 file.
`OnsiteTerms.max_range`()	Maximum range of the terms.
`OnsiteTerms.remove_zeros`([tol_zero])	Remove entries close to 0 from `onsite_terms`.
`OnsiteTerms.save_hdf5`(hdf5_saver, h5gr, subpath)	Export self into a HDF5 file.
`OnsiteTerms.to_Arrays`(sites)	Convert the `onsite_terms` into a list of np_conserved Arrays.
`OnsiteTerms.to_TermList`()	Convert `onsite_terms` into a `TermList`.

class tenpy.networks.terms.OnsiteTerms(L)[source]

Bases: Hdf5Exportable

Operator names, site indices and strengths representing onsite terms.

Represents a sum of onsite terms where the operators are only given by their name (in the form of a string). What the operator represents is later given by a list of Site with get_op().

Parameters:: L (int) – Number of sites.

L

Number of sites.

Type:: int

onsite_terms

Filled by meth:add_onsite_term. For each index i a dictionary {'opname': strength} defining the onsite terms.

Type:: list of dict

max_range()[source]

Maximum range of the terms.

In this case 0.

add_onsite_term(strength, i, op)[source]

Add a onsite term on a given MPS site.

Parameters:

strength (float) – The strength of the term.
i (int) – The MPS index of the site on which the operator acts. We require 0 <= i < L.
op (str) – Name of the involved operator.

add_to_graph(graph)[source]

Add terms from onsite_terms to an MPOGraph.

Parameters:: graph (MPOGraph) – The graph into which the terms from onsite_terms should be added.

to_Arrays(sites)[source]

Convert the onsite_terms into a list of np_conserved Arrays.

Parameters:: sites (list of Site) – Defines the local Hilbert space for each site. Used to translate the operator names into Array.
Returns:: onsite_arrays – Onsite terms represented by self. Entry i of the list lives on sites[i].
Return type:: list of Array

remove_zeros(tol_zero=1e-15)[source]

Remove entries close to 0 from onsite_terms.

Parameters:: tol_zero (float) – Entries in onsite_terms with strength < tol_zero are considered to be zero and removed.

add_to_nn_bond_Arrays(H_bond, sites, finite, distribute=(0.5, 0.5))[source]

Add self.onsite_terms into nearest-neighbor bond arrays.

Parameters:

H_bond (list of {Array | None}) – The coupling_terms rewritten as sum_i H_bond[i] for MPS indices i. H_bond[i] acts on sites (i-1, i), None represents 0. Legs of each H_bond[i] are ['p0', 'p0*', 'p1', 'p1*']. Modified in place.
sites (list of Site) – Defines the local Hilbert space for each site. Used to translate the operator names into Array.
distribute ((float, float)) – How to split the onsite terms (in the bulk) into the bond terms to the left (distribute[0]) and right (distribute[1]).
finite (bool) – Boundary conditions of the MPS, MPS.finite. If finite, we distribute the onsite term of the

to_TermList()[source]

Convert onsite_terms into a TermList.

Returns:: term_list – Representation of the terms as a list of terms.
Return type:: TermList

classmethod from_hdf5(hdf5_loader, h5gr, subpath)[source]

Load instance from a HDF5 file.

This method reconstructs a class instance from the data saved with save_hdf5().

Parameters:

hdf5_loader (Hdf5Loader) – Instance of the loading engine.
h5gr (Group) – HDF5 group which is represent the object to be constructed.
subpath (str) – The name of h5gr with a '/' in the end.

Returns:

obj – Newly generated class instance containing the required data.

Return type:

cls

save_hdf5(hdf5_saver, h5gr, subpath)[source]

Export self into a HDF5 file.

This method saves all the data it needs to reconstruct self with from_hdf5().

This implementation saves the content of __dict__ with save_dict_content(), storing the format under the attribute 'format'.

Parameters:

hdf5_saver (Hdf5Saver) – Instance of the saving engine.
h5gr (:class`Group`) – HDF5 group which is supposed to represent self.
subpath (str) – The name of h5gr with a '/' in the end.