HamiltonianPhaseEstimationResult

qiskit.algorithms.HamiltonianPhaseEstimationResult(phase_estimation_result, phase_estimation_scale, id_coefficient)

Bases: AlgorithmResult

Store and manipulate results from running HamiltonianPhaseEstimation.

This API of this class is nearly the same as PhaseEstimatorResult, differing only in the presence of an additional keyword argument in the methods. If scaled is False, then the phases are not translated and scaled to recover the eigenvalues of the Hamiltonian. Instead phi in $[0, 1)$ is returned, as is the case when then unitary is not derived from a Hamiltonian.

This class is meant to be instantiated via HamiltonianPhaseEstimation.estimate.

Parameters

• phase_estimation_result (PhaseEstimationResult) – The result object returned by PhaseEstimation.estimate.
• phase_estimation_scale (PhaseEstimationScale) – object used to scale phases to obtain eigenvalues.
• id_coefficient (float (opens in a new tab)) – The coefficient of the identity term in the Hamiltonian. Eigenvalues are computed without this term so that the coefficient must added to give correct eigenvalues. This is done automatically when retrieving eigenvalues.

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Attributes

most_likely_eigenvalue

The most likely eigenvalue of the Hamiltonian.

This method calls most_likely_phase and scales the result to obtain an eigenvalue.

Returns

The most likely eigenvalue of the Hamiltonian.

phase

The most likely phase of the unitary corresponding to the Hamiltonian.

Returns

The most likely phase.

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Methods

combine

combine(result)

Any property from the argument that exists in the receiver is updated. :param result: Argument result with properties to be set.

Raises

TypeError (opens in a new tab) – Argument is None

filter_phases

filter_phases(cutoff=0.0, scaled=True, as_float=True)

Filter phases as does PhaseEstimatorResult.filter_phases, with the addition that phi is shifted and translated to return eigenvalues of the Hamiltonian.

Parameters

• cutoff (float (opens in a new tab)) – Minimum weight of number of counts required to keep a bit string. The default value is 0.0.
• scaled (bool (opens in a new tab)) – If False, return phi in $[0, 1)$ rather than the eigenvalues of the Hamiltonian.
• as_float (bool (opens in a new tab)) – If True, returned keys are floats in $[0.0, 1.0)$. If False returned keys are bit strings.

Raises

ValueError (opens in a new tab) – if as_float is False and scaled is True.

Returns

A dict of filtered phases.

Return type

Mapping[str (opens in a new tab) | float (opens in a new tab), float (opens in a new tab)]