F2QSynthesis

class F2QSynthesis(config=None)

Bases: GenericPass[DAGCircuit, DAGCircuit]

A transpilation pass to map fermion-based circuit instructions to qubit-based ones.

This transpilation pass works similarly to Qiskit’s HighLevelSynthesis pass; given an input FermionicDAGCircuit, it iterates the contained instructions and delegates the translation to qubit-based instructions to matching methods. The insertion of the qubit-based circuit instructions into the output DAGCircuit is also left to the plugin method. This pass will merely have prepared the QuantumRegister according to the global transpilation F2QLayout setting.

Usage

There are two ways to configure the plugins used by this transpiler pass. The examples below show the equivalent configuration to the generate_preset_jw_pass_manager().

Providing a config during initialization:

>>> from qiskit_fermions.mappers.library import jordan_wigner
>>> from qiskit_fermions.transpiler import passes
>>>
>>> config = {
...     "Evolution": ("MapperFn", (jordan_wigner,)),
...     "InitializeModes": "TrivialOccupation",
...     "OrbitalRotation": "GivensDecomposition",
... }
>>> synth = passes.F2QSynthesis(config)

Manually populating the methods attribute:

>>> from qiskit_fermions.mappers.library import jordan_wigner
>>> from qiskit_fermions.transpiler import passes
>>>
>>> synth = passes.F2QSynthesis()
>>> synth.methods["Evolution"] = passes.MapperFnEvolutionSynthesis(jordan_wigner)
>>> synth.methods["InitializeModes"] = passes.TrivialOccupationInitializeModesSynthesis()
>>> synth.methods["OrbitalRotation"] = passes.GivensDecompositionOrbitalRotationSynthesis()

Through this manual approach it is also possible to inject custom F2QSynthesisPlugin implementations without requiring them to be registered through an entry-point.

Initializing this transpiler pass can be done with the arguments listed below.

Parameters

config (F2QSynthesisConfig | None) – an optional dictionary to pre-populate the methods with plugins provided by the F2QSynthesisPluginManager.

Attributes

methods

Type: dict[str, F2QSynthesisPlugin]

A dictionary of fermion-to-qubit circuit instruction transpilation methods.

For this transpilation pass to have any effect, this dictionary must be populated with instances of the F2QSynthesisPlugin protocol. The keys of this dictionary correspond to the __name__ of a circuit instruction.

All available transpilation plugins are managed by the F2QSynthesisPluginManager.

Note

This dictionary is empty by default! You can pre-populate it with plugins provided by the F2QSynthesisPluginManager by providing a config argument during initialization of this transpiler pass instance.

Methods

run

run(dag)

Runs this transpilation pass.

Parameters

dag (DAGCircuit) – the input circuit with fermion-based instructions. Only DAGOpNode with FermionicGate instances as their op are supported.

Returns

The output circuit with qubit-based instructions.

Raises

ValueError – when a DAGOpNode is encountered whose op is not of type FermionicGate.
TypeError – when a FermionicGate type is encountered for which no translation plugin is present in methods.

Return type

DAGCircuit

Inherited Methods

execute

execute(passmanager_ir, state, callback=None)

Execute optimization task for input Qiskit IR.

Parameters

passmanager_ir (IR) – Qiskit IR to optimize.
state (PassManagerState) – State associated with workflow execution by the pass manager itself.
callback (Callable[[Task, IR_OUT, PropertySet, float, int], None] | None) – A callback function which is called per execution of optimization task.