qiskit.algorithms.HamiltonianPhaseEstimation.estimate

HamiltonianPhaseEstimation.estimate(hamiltonian, state_preparation=None, evolution=None, bound=None)

Run the Hamiltonian phase estimation algorithm.

Parameters

• hamiltonian (OperatorBase) – A Hermitian operator.

• state_preparation (Optional[StateFn]) – The StateFn to be prepared, whose eigenphase will be measured. If this parameter is omitted, no preparation circuit will be run and input state will be the all-zero state in the computational basis.

• evolution (Optional[EvolutionBase]) – An evolution converter that generates a unitary from hamiltonian. If None, then the default PauliTrotterEvolution is used.

• bound (Optional[float]) – An upper bound on the absolute value of the eigenvalues of hamiltonian. If omitted, then hamiltonian must be a Pauli sum, or a PauliOp, in which case a bound will be computed. If hamiltonian is a MatrixOp, then bound may not be None. The tighter the bound, the higher the resolution of computed phases.

Return type

HamiltonianPhaseEstimationResult

Returns

HamiltonianPhaseEstimationResult instance containing the result of the estimation and diagnostic information.

Raises

• ValueError – If bound is None and hamiltonian is not a Pauli sum, i.e. a PauliSumOp or a SummedOp whose terms are of type PauliOp.

• TypeError – If evolution is not of type EvolutionBase.