qiskit.aqua.algorithms.IQPE¶

class IQPE(operator=None, state_in=None, num_time_slices=1, num_iterations=1, expansion_mode='suzuki', expansion_order=2, shallow_circuit_concat=False, quantum_instance=None)[ソース]¶

The Iterative Quantum Phase Estimation algorithm.

IQPE, as its name suggests, iteratively computes the phase so as to require fewer qubits. It has the same set of parameters as QPE, except for the number of ancillary qubits num_ancillae, being replaced by num_iterations and that an Inverse Quantum Fourier Transform (IQFT) is not used for IQPE.

Reference:

[1]: Dobsicek et al. (2006), Arbitrary accuracy iterative phase estimation algorithm as a two: qubit benchmark, arxiv/quant-ph/0610214

パラメータ

operator (Union[OperatorBase, LegacyBaseOperator, None]) – The hamiltonian Operator
state_in (Union[QuantumCircuit, InitialState, None]) – An InitialState component representing an initial quantum state.
num_time_slices (int) – The number of time slices, has a minimum value of 1.
num_iterations (int) – The number of iterations, has a minimum value of 1.
expansion_mode (str) – The expansion mode (『trotter』|』suzuki』)
expansion_order (int) – The suzuki expansion order, has a min. value of 1.
shallow_circuit_concat (bool) – Set True to use shallow (cheap) mode for circuit concatenation of evolution slices. By default this is False.
quantum_instance (Union[QuantumInstance, Backend, BaseBackend, None]) – Quantum Instance or Backend

__init__(operator=None, state_in=None, num_time_slices=1, num_iterations=1, expansion_mode='suzuki', expansion_order=2, shallow_circuit_concat=False, quantum_instance=None)[ソース]¶

パラメータ

operator (Union[OperatorBase, LegacyBaseOperator, None]) – The hamiltonian Operator
state_in (Union[QuantumCircuit, InitialState, None]) – An InitialState component representing an initial quantum state.
num_time_slices (int) – The number of time slices, has a minimum value of 1.
num_iterations (int) – The number of iterations, has a minimum value of 1.
expansion_mode (str) – The expansion mode (『trotter』|』suzuki』)
expansion_order (int) – The suzuki expansion order, has a min. value of 1.
shallow_circuit_concat (bool) – Set True to use shallow (cheap) mode for circuit concatenation of evolution slices. By default this is False.
quantum_instance (Union[QuantumInstance, Backend, BaseBackend, None]) – Quantum Instance or Backend

Methods

`__init__`([operator, state_in, …])	type operator `Union`[`OperatorBase`, `LegacyBaseOperator`, `None`]
`compute_minimum_eigenvalue`([operator, …])	Computes minimum eigenvalue.
`construct_circuit`([k, omega, measurement])	Construct the kth iteration Quantum Phase Estimation circuit.
`run`([quantum_instance])	Execute the algorithm with selected backend.
`set_backend`(backend, **kwargs)	Sets backend with configuration.
`supports_aux_operators`()	Whether computing the expectation value of auxiliary operators is supported.

Attributes

`aux_operators`	Returns aux operators
`backend`	Returns backend.
`operator`	Returns operator
`quantum_instance`	Returns quantum instance.
`random`	Return a numpy random.

property aux_operators¶

Returns aux operators

戻り値の型: Optional[List[Union[OperatorBase, LegacyBaseOperator]]]

property backend¶

Returns backend.

戻り値の型: Union[Backend, BaseBackend]

compute_minimum_eigenvalue(operator=None, aux_operators=None)[ソース]¶

Computes minimum eigenvalue. Operator and aux_operators can be supplied here and if not None will override any already set into algorithm so it can be reused with different operators. While an operator is required by algorithms, aux_operators are optional. To 『remove』 a previous aux_operators array use an empty list here.

パラメータ

operator (Union[OperatorBase, LegacyBaseOperator, None]) – If not None replaces operator in algorithm
aux_operators (Optional[List[Union[OperatorBase, LegacyBaseOperator]]]) – If not None replaces aux_operators in algorithm

戻り値の型

MinimumEigensolverResult

戻り値

MinimumEigensolverResult

construct_circuit(k=None, omega=0, measurement=False)[ソース]¶

Construct the kth iteration Quantum Phase Estimation circuit.

For details of parameters, please see Fig. 2 in https://arxiv.org/pdf/quant-ph/0610214.pdf.

パラメータ

k (Optional[int]) – the iteration idx.
omega (float) – the feedback angle.
measurement (bool) – Boolean flag to indicate if measurement should be included in the circuit.

戻り値

the quantum circuit per iteration

戻り値の型

QuantumCircuit

property operator¶

Returns operator

戻り値の型: Union[OperatorBase, LegacyBaseOperator, None]

property quantum_instance¶

Returns quantum instance.

戻り値の型: Optional[QuantumInstance]

property random¶: Return a numpy random.

run(quantum_instance=None, **kwargs)¶

Execute the algorithm with selected backend.

パラメータ

quantum_instance (Union[QuantumInstance, Backend, BaseBackend, None]) – the experimental setting.
kwargs (dict) – kwargs

戻り値

results of an algorithm.

戻り値の型

dict

例外

AquaError – If a quantum instance or backend has not been provided

set_backend(backend, **kwargs)¶

Sets backend with configuration.

戻り値の型: None

classmethod supports_aux_operators()¶

Whether computing the expectation value of auxiliary operators is supported.

If the minimum eigensolver computes an eigenstate of the main operator then it can compute the expectation value of the aux_operators for that state. Otherwise they will be ignored.

戻り値の型: bool
戻り値: True if aux_operator expectations can be evaluated, False otherwise