LayerModel¶

class LayerModel(model_params)[source]¶

Bases: CouplingMPOModel, NearestNeighborModel

A model for representing a layer of time-evolution interactions.

Essentially, this class is a simple wrapper of tenpy.models.model.CouplingMPOModel and tenpy.models.model.NearestNeighborModel. Its main purpose is to provide a simple interface for constructing a TeNPy-compatible Hamiltonian from Qiskit objects.

Methods

calc_H_bond(tol_zero=1e-15)[source]¶

Calculate the interaction Hamiltonian based on the coupling and onsite terms.

Essentially, this class overwrites calc_H_bond() and takes care of removing even or odd bond interaction Hamiltonians depending on the value of keep_only_odd (see tenpy_layers for more details).

Parameters:: tol_zero (float) – the threshold for values considered to be zero.
Returns:: The list of interaction Hamiltonians for all bonds.
Return type:: list

classmethod from_quantum_circuit(circuit, *, scaling_factor=1.0, **kwargs)[source]¶

Construct a LayerModel from a QuantumCircuit.

You can see an example of this function in action in the docs of tenpy_layers.

Parameters:

circuit (QuantumCircuit) – the quantum circuit to parse.
scaling_factor (float) – a factor with which to scale the term strengths. This can be used to apply (for example) a time step scaling factor. It may also be used (e.g.) to split onsite terms into two layers (even and odd) with $0.5$ of the strength, each.
kwargs – any additional keyword arguments to pass to the LayerModel constructor.

Returns:

A new LayerModel instance.

Raises:

NotImplementedError – if an unsupported quantum gate is encountered.

Return type:

LayerModel

init_sites(model_params)[source]¶

Initializes the sites of this Hamiltonian.

See init_sites() for more details.

Caution

Currently, this enforces Sz conservation on all sites.

Parameters:: model_params (Config) – the model parameters.
Returns:: The site to be used internally.
Return type:: Site

init_terms(model_params)[source]¶

Initializes the terms of this Hamiltonian.

See init_terms() for more details.

Parameters:: model_params (Config) – the model parameters.
Return type:: None