add-backend-estimator-v2-26cf14a3612bb81a.yaml

---
features:
  - |
    The implementation :class:`~.BackendEstimatorV2` of :class:`~.BaseEstimatorV2` was added.
    This estimator supports :class:`~.BackendV1` and :class:`~.BackendV2`.

    .. code-block:: python

      import numpy as np
      from qiskit import transpile
      from qiskit.circuit.library import IQP
      from qiskit.primitives import BackendEstimatorV2
      from qiskit.providers.fake_provider import Fake7QPulseV1
      from qiskit.quantum_info import SparsePauliOp, random_hermitian

      backend = Fake7QPulseV1()
      estimator = BackendEstimatorV2(backend=backend)
      n_qubits = 5
      mat = np.real(random_hermitian(n_qubits, seed=1234))
      circuit = IQP(mat)
      observable = SparsePauliOp("Z" * n_qubits)
      isa_circuit = transpile(circuit, backend=backend, optimization_level=1)
      isa_observable = observable.apply_layout(isa_circuit.layout)
      job = estimator.run([(isa_circuit, isa_observable)], precision=0.01)
      result = job.result()
      print(f"> Expectation value: {result[0].data.evs}")
      print(f"> Standard error: {result[0].data.stds}")
      print(f"> Metadata: {result[0].metadata}")