Skip to main contentIBM Quantum Documentation
You are viewing the API reference for an old version of Qiskit SDK. Switch to latest version

Eigensolver

class Eigensolver

GitHub(opens in a new tab)

Bases: abc.ABC

The eigensolver interface.

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


Methods

compute_eigenvalues

abstract Eigensolver.compute_eigenvalues(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 | PauliSumOp) – Qubit operator of the observable.
  • aux_operators (ListOrDict[BaseOperator | PauliSumOp] | None) – Optional list of auxiliary operators to be evaluated with the eigenstate 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.

Return type

EigensolverResult

Returns

An eigensolver result.

supports_aux_operators

classmethod Eigensolver.supports_aux_operators()

Whether computing the expectation value of auxiliary operators is supported.

If the eigensolver computes the eigenvalues 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.

Was this page helpful?
Report a bug or request content on GitHub.