MinimumEigensolver

class MinimumEigensolver

Bases: ABC

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.

Methods

abstract compute_minimum_eigenvalue(operator, aux_operators=None)

Computes the minimum eigenvalue. The operator and aux_operators are supplied here. While an operator is required by algorithms, aux_operators are optional.

Parameters:

• operator (BaseOperator) – Qubit operator of the observable.

• aux_operators (List[BaseOperator | None] | Dict[str, BaseOperator] | None) – Optional list of auxiliary operators to be evaluated with the parameters of the minimum eigenvalue main result and their expectation values returned. For instance in chemistry these can be dipole operators and total particle count operators, so we can get values for these at the ground state.

Returns:

A minimum eigensolver result.

Return type:

MinimumEigensolverResult

classmethod supports_aux_operators()

Whether computing the expectation value of auxiliary operators is supported.

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

Returns:

True if aux_operator expectations can be evaluated, False otherwise

Return type:

bool