Merge branch 'main' into restore_arm64_macos

qiskit_aer/aerprovider.py

@@ -14,7 +14,7 @@
 """Provider for Aer backends."""
 
 
-from qiskit.providers import ProviderV1 as Provider
+from qiskit.providers import QiskitBackendNotFoundError
 from qiskit.providers.providerutils import filter_backends
 
 from .backends.aer_simulator import AerSimulator
@@ -23,10 +23,11 @@
 from .backends.unitary_simulator import UnitarySimulator
 
 
-class AerProvider(Provider):
+class AerProvider:
     """Provider for Aer backends."""
 
     _BACKENDS = None
+    version = 1
 
     @staticmethod
     def _get_backends():
@@ -64,10 +65,40 @@ def _get_backends():
         return AerProvider._BACKENDS
 
     def get_backend(self, name=None, **kwargs):
-        return super().get_backend(name=name, **kwargs)
+        """Return a single Aer backend matching the specified filtering.
+
+        Args:
+            name (str): name of the Aer backend.
+            **kwargs: dict used for filtering.
+
+        Returns:
+            Backend: an Aer backend matching the filtering.
+
+        Raises:
+            QiskitBackendNotFoundError: if no backend could be found or
+                more than one backend matches the filtering criteria.
+        """
+        backends = self.backends(name, **kwargs)
+        if len(backends) > 1:
+            raise QiskitBackendNotFoundError("More than one backend matches the criteria")
+        if not backends:
+            raise QiskitBackendNotFoundError("No backend matches the criteria")
+
+        return backends[0]
 
     def backends(self, name=None, filters=None, **kwargs):
-        # pylint: disable=arguments-differ
+        """Return a list of backends matching the specified filtering.
+
+        Args:
+            name (str): name of the backend.
+            filters (callable): filtering conditions as a callable.
+            **kwargs: dict used for filtering.
+
+        Returns:
+            list[Backend]: a list of Backends that match the filtering
+                criteria.
+        """
+        # pylint: disable=unused-argument
         # Instantiate a new backend instance so if config options
         # are set they will only last as long as that backend object exists
         backends = []

qiskit_aer/backends/aer_simulator.py

@@ -855,7 +855,9 @@ def from_backend(cls, backend, **options):
                 open_pulse=False,
                 memory=False,
                 max_shots=int(1e6),
-                coupling_map=list(backend.coupling_map.get_edges()),
+                coupling_map=(
+                    None if backend.coupling_map is None else list(backend.coupling_map.get_edges())
+                ),
                 max_experiments=backend.max_circuits,
                 description=description,
             )

qiskit_aer/primitives/estimator_v2.py

@@ -76,7 +76,10 @@ def __init__(
     def from_backend(cls, backend, **options):
         """make new sampler that uses external backend"""
         estimator = cls(**options)
-        estimator._backend = AerSimulator.from_backend(backend)
+        if isinstance(backend, AerSimulator):
+            estimator._backend = backend
+        else:
+            estimator._backend = AerSimulator.from_backend(backend)
         return estimator
 
     @property

qiskit_aer/primitives/sampler_v2.py

@@ -97,7 +97,10 @@ def __init__(
     def from_backend(cls, backend, **options):
         """make new sampler that uses external backend"""
         sampler = cls(**options)
-        sampler._backend = AerSimulator.from_backend(backend)
+        if isinstance(backend, AerSimulator):
+            sampler._backend = backend
+        else:
+            sampler._backend = AerSimulator.from_backend(backend)
         return sampler
 
     @property

releasenotes/notes/fix_from_backend-a885d43caf390873.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    `from_backend` function of V2 primitives are fixed to accept AerSimulator
+    objects as input so that user can define simulator objects outside of
+    primitives

releasenotes/notes/providerABC-61311d8e5ae56d71.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    The class :class:`.AerProvider` does not implement Qiskit's ``Provider``, as it is now deprecated.
+    This fix removes the raising of the warning from Qiskit.