qiskit.chemistry.transformations.BosonicTransformation

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

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

Parameter

• 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)

Parameter

• 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)

Rückgabetyp

Union[int, List[int]]

build_hopping_operators(excitations='sd')

Parameter

excitations (Union[str, List[List[int]]]) –

Rückgabetyp

Tuple[Dict[str, WeightedPauliOperator], Dict, Dict[str, List[List[int]]]]

Rückgabe

Dict of hopping operators, dict of commutativity types and dict of excitation indices

property commutation_rule

Getter of the commutation rule

Rückgabetyp

bool

get_default_filter_criterion()

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.

Rückgabetyp

Optional[Callable[[Union[List, ndarray], float, Optional[List[float]]], bool]]

interpret(raw_result)

Interprets an EigenstateResult in the context of this transformation.

Parameter

raw_result (Union[EigenstateResult, EigensolverResult, MinimumEigensolverResult]) – an eigenstate result object.

Rückgabetyp

VibronicStructureResult

Rückgabe

An vibronic structure result.

property num_modes

the number of modes

Type

Returns

Rückgabetyp

int

transform(driver, aux_operators=None)

Transformation to qubit operator from the driver

Parameter

• driver (BaseDriver) – BaseDriver

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

Rückgabetyp

Tuple[WeightedPauliOperator, List[WeightedPauliOperator]]

Rückgabe

qubit operator, auxiliary operators

property untapered_qubit_op

Getter for the untapered qubit operator