# qiskit.algorithms.IterativePhaseEstimation.estimate¶

IterativePhaseEstimation.estimate(unitary, state_preparation)[source]

Estimate the eigenphase of the input unitary and initial-state pair.

Parameters
• unitary (QuantumCircuit) – The circuit representing the unitary operator whose eigenvalue (via phase) will be measured.

• state_preparation (QuantumCircuit) – The circuit that prepares the state 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.

Return type

IterativePhaseEstimationResult

Returns

Estimated phase in an IterativePhaseEstimationResult object.