qiskit_aer.library.save_expectation_value_variance

save_expectation_value_variance(self, operator, qubits, label='expectation_value_variance', unnormalized=False, pershot=False, conditional=False)

Save the expectation value of a Hermitian operator.

Parameters

• operator (Pauli orSparsePauliOp orOperator) – a Hermitian operator.
• qubits (list) – circuit qubits to apply instruction.
• label (str) – the key for retrieving saved data from results.
• unnormalized (bool) – If True return save the unnormalized accumulated or conditional accumulated expectation value and variance over all shot [Default: False].
• pershot (bool) – if True save a list of expectation values and variances for each shot of the simulation rather than the average over all shots [Default: False].
• conditional (bool) – if True save the data conditional on the current classical register values [Default: False].

Returns

with attached instruction.

Return type

QuantumCircuit

Raises

ExtensionError – if the input operator is invalid or not Hermitian.