qiskit.chemistry.transformations.BosonicTransformation¶

class BosonicTransformation(qubit_mapping=<BosonicQubitMappingType.DIRECT: 'direct'>, transformation_type=<BosonicTransformationType.HARMONIC: 'harmonic'>, basis_size=2, truncation=3)[source]¶

A vibronic Hamiltonian operator representing the energy of the nuclei in the molecule

Parameters

qubit_mapping (BosonicQubitMappingType) – a string giving the type of mapping (only the ‘direct’ mapping is implemented at this point)
transformation_type (BosonicTransformationType) – a string giving the modal basis. The Hamiltonian is expressed in this basis.
basis_size (Union[int, List[int]]) – define the number of modals per mode. If the number of modals is the same for each mode, then only an int is required. However, if the number of modals differ depending on the mode basis_size should be a list of int, for example: [3,4] means 2 modes: first mode has 3 modals, second mode has 4 modals.
truncation (int) – where is the Hamiltonian expansion truncation (1 for having only 1-body terms, 2 for having on 1- and 2-body terms…)

__init__(qubit_mapping=<BosonicQubitMappingType.DIRECT: 'direct'>, transformation_type=<BosonicTransformationType.HARMONIC: 'harmonic'>, basis_size=2, truncation=3)[source]¶

Parameters

qubit_mapping (BosonicQubitMappingType) – a string giving the type of mapping (only the ‘direct’ mapping is implemented at this point)
transformation_type (BosonicTransformationType) – a string giving the modal basis. The Hamiltonian is expressed in this basis.
basis_size (Union[int, List[int]]) – define the number of modals per mode. If the number of modals is the same for each mode, then only an int is required. However, if the number of modals differ depending on the mode basis_size should be a list of int, for example: [3,4] means 2 modes: first mode has 3 modals, second mode has 4 modals.
truncation (int) – where is the Hamiltonian expansion truncation (1 for having only 1-body terms, 2 for having on 1- and 2-body terms…)

Methods

`__init__`([qubit_mapping, …])	type qubit_mapping `BosonicQubitMappingType`
`build_hopping_operators`([excitations])	type excitations `Union`[`str`, `List`[`List`[`int`]]]
`get_default_filter_criterion`()	Returns a default filter criterion method to filter the eigenvalues computed by the eigen solver.
`interpret`(raw_result)	Interprets an EigenstateResult in the context of this transformation.
`transform`(driver[, aux_operators])	Transformation to qubit operator from the driver

Attributes

`basis`	returns the basis (number of modals per mode)
`commutation_rule`	Getter of the commutation rule
`num_modes`	the number of modes
`untapered_qubit_op`	Getter for the untapered qubit operator

property basis¶

returns the basis (number of modals per mode)

Return type: Union[int, List[int]]

build_hopping_operators(excitations='sd')[source]¶

Parameters: excitations (Union[str, List[List[int]]]) –
Return type: Tuple[Dict[str, WeightedPauliOperator], Dict, Dict[str, List[List[int]]]]
Returns: Dict of hopping operators, dict of commutativity types and dict of excitation indices

property commutation_rule¶

Getter of the commutation rule

Return type: bool

get_default_filter_criterion()[source]¶

Returns a default filter criterion method to filter the eigenvalues computed by the eigen solver. For more information see also aqua.algorithms.eigen_solvers.NumPyEigensolver.filter_criterion. In the fermionic case the default filter ensures that the number of particles is being preserved.

Return type: Optional[Callable[[Union[List, ndarray], float, Optional[List[float]]], bool]]

interpret(raw_result)[source]¶

Interprets an EigenstateResult in the context of this transformation.

Parameters: raw_result (Union[EigenstateResult, EigensolverResult, MinimumEigensolverResult]) – an eigenstate result object.
Return type: VibronicStructureResult
Returns: An vibronic structure result.

property num_modes¶

the number of modes

Type: Returns
Return type: int

transform(driver, aux_operators=None)[source]¶

Transformation to qubit operator from the driver

Parameters

driver (BaseDriver) – BaseDriver
aux_operators (Optional[List[Any]]) – Optional additional aux ops to evaluate

Return type

Tuple[WeightedPauliOperator, List[WeightedPauliOperator]]

Returns

qubit operator, auxiliary operators

property untapered_qubit_op¶: Getter for the untapered qubit operator