# qiskit.aqua.algorithms.MinimumEigensolver¶

class MinimumEigensolver[source]

The Minimum Eigensolver Interface.

Algorithms that can compute a minimum eigenvalue for an operator may implement this interface to allow different algorithms to be used interchangeably.

__init__()

Initialize self. See help(type(self)) for accurate signature.

Methods

 Initialize self. compute_minimum_eigenvalue([operator, …]) Computes minimum eigenvalue. Whether computing the expectation value of auxiliary operators is supported.

Attributes

 aux_operators Returns the auxiliary operators. operator Return the operator.
abstract property aux_operators

Returns the auxiliary operators.

Return type

Optional[List[Optional[OperatorBase]]]

abstract compute_minimum_eigenvalue(operator=None, aux_operators=None)[source]

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.

Parameters
• operator (Union[OperatorBase, LegacyBaseOperator, None]) – If not None replaces operator in algorithm

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

Return type

MinimumEigensolverResult

Returns

MinimumEigensolverResult

abstract property operator

Return the operator.

Return type

Union[OperatorBase, LegacyBaseOperator, None]

classmethod supports_aux_operators()[source]

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.

Return type

bool

Returns

True if aux_operator expectations can be evaluated, False otherwise