Estimator

class Estimator(circuits: Iterable[QuantumCircuit] | QuantumCircuit | None = None, observables: Iterable[SparsePauliOp] | SparsePauliOp | None = None, parameters: Iterable[Iterable[Parameter]] | None = None, **kwargs)

Bases: qiskit.primitives.base.base_estimator.BaseEstimator

Aer implmentation of Estimator.

Run Options

• shots (None or int) – The number of shots. If None and approximation is True, it calculates the exact expectation values. Otherwise, it calculates expectation values with sampling.

• seed (int) – Set a fixed seed for the sampling.

Note

Precedence of seeding for seed_simulator is as follows:

1. seed_simulator in runtime (i.e. in __call__())

2. seed in runtime (i.e. in __call__())

3. seed_simulator of backend_options.

4. default.

seed is also used for sampling from a normal distribution when approximation is True.

Parameters

• circuits – Quantum circuits that represent quantum states.

• observables – Observables.

• parameters – Parameters of quantum circuits, specifying the order in which values will be bound. Defaults to [circ.parameters for circ in circuits] The indexing is such that parameters[i, j] is the j-th formal parameter of circuits[i].

• backend_options – Options passed to AerSimulator.

• transpile_options – Options passed to transpile.

• run_options – Options passed to run.

• approximation – If True, it calculates expectation values with normal distribution approximation.

• skip_transpilation – If True, transpilation is skipped.

Methods

close	Close the session and free resources
run	Run the job of the estimation of expectation value(s).
set_options	Set options values for the estimator.

Attributes

circuits

Quantum circuits that represents quantum states.

Returns

The quantum circuits.

observables

Observables to be estimated.

Returns

The observables.

options

Return options values for the estimator.

Return type

Options

Returns

options

parameters

Parameters of the quantum circuits.

Returns

Parameters, where parameters[i][j] is the j-th parameter of the i-th circuit.