Provider: remove deprecated ProviderV1 inheritance (#160)

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Unreleased
 
 * Docs: add examples on setting run options in primitives (#156)
+* Provider: remove `ProviderV1` inheritance (#160)
 
 ## qiskit-aqt-provider v1.4.0
 

docs/guide.rst

@@ -222,7 +222,7 @@ AQT backends only natively implement a limited but complete set of quantum gates
 
    print(list(backend.target.operation_names))
 
-.. warning:: For implementation reasons, the transpilation target declares :class:`RXGate <qiskit.circuit.library.RXGate>` as basis gate. The AQT API, however, only accepts the more general :class:`RGate <qiskit.circuit.library.RGate>`, in addition to :class:`RZGate <qiskit.circuit.library.RZGate>`, the entangling :class:`RXXGate <qiskit.circuit.library.RXXGate>`, and the :class:`Measure <qiskit.circuit.library.Measure>` operation.
+.. warning:: For implementation reasons, the transpilation target declares :class:`RXGate <qiskit.circuit.library.RXGate>` as basis gate. The AQT API, however, only accepts the more general :class:`RGate <qiskit.circuit.library.RGate>`, in addition to :class:`RZGate <qiskit.circuit.library.RZGate>`, the entangling :class:`RXXGate <qiskit.circuit.library.RXXGate>`, and the :class:`Measure <qiskit.circuit.measure.Measure>` operation.
 
 The transpiler's entry point is the :func:`qiskit.transpile <qiskit.compiler.transpile>` function. The optimization level can be tuned using the ``optimization_level=0,1,2,3`` argument. One can inspect how the circuit is converted from the original one:
 
@@ -299,7 +299,7 @@ Common limitations
 Reset operations are not supported
 ----------------------------------
 
-Because AQT backends do not support in-circuit state reinitialization of specific qubits, the :class:`Reset <qiskit.circuit.library.Reset>` operation is not supported. The Qiskit transpiler will fail synthesis for circuits using it (e.g. through :meth:`QuantumCircuit.initialize <qiskit.circuit.QuantumCircuit.initialize>`) when targeting AQT backends.
+Because AQT backends do not support in-circuit state reinitialization of specific qubits, the :class:`Reset <qiskit.circuit.reset.Reset>` operation is not supported. The Qiskit transpiler will fail synthesis for circuits using it (e.g. through :meth:`QuantumCircuit.initialize <qiskit.circuit.QuantumCircuit.initialize>`) when targeting AQT backends.
 
 AQT backends always prepare the quantum register in the :math:`|0\rangle\otimes\cdots\otimes|0\rangle` state. Thus, :meth:`QuantumCircuit.prepare_state <qiskit.circuit.QuantumCircuit.prepare_state>` is an alternative to :meth:`QuantumCircuit.initialize <qiskit.circuit.QuantumCircuit.initialize>` as first instruction in the circuit:
 

qiskit_aqt_provider/aqt_provider.py

@@ -31,7 +31,7 @@
 
 import dotenv
 import httpx
-from qiskit.providers import ProviderV1
+from qiskit.providers.exceptions import QiskitBackendNotFoundError
 from tabulate import tabulate
 from typing_extensions import TypeAlias, override
 
@@ -139,7 +139,7 @@ def table(self) -> list[list[str]]:
         return table
 
 
-class AQTProvider(ProviderV1):
+class AQTProvider:
     """Provider for backends from Alpine Quantum Technologies (AQT)."""
 
     # Set AQT_PORTAL_URL environment variable to override
@@ -282,3 +282,35 @@ def backends(
                 )
 
         return BackendsTable(backends)
+
+    def get_backend(
+        self,
+        name: Optional[Union[str, Pattern[str]]] = None,
+        *,
+        backend_type: Optional[Literal["device", "simulator", "offline_simulator"]] = None,
+        workspace: Optional[Union[str, Pattern[str]]] = None,
+    ) -> AQTResource:
+        """Return a single backend matching the specified filtering.
+
+        Args:
+            name: filter for the backend name.
+            backend_type: if given, restrict the search to the given backend type.
+            workspace: if given, restrict to matching workspace IDs.
+
+        Returns:
+            Backend: backend matching the filtering.
+
+        Raises:
+            QiskitBackendNotFoundError: if no backend could be found or
+                more than one backend matches the filtering criteria.
+        """
+        # From: https://github.com/Qiskit/qiskit/blob/8e3218bc0798b0612edf446db130e95ac9404968/qiskit/providers/provider.py#L53
+        # after ProviderV1 deprecation.
+        # See: https://github.com/Qiskit/qiskit/pull/12145.
+        backends = self.backends(name, backend_type=backend_type, workspace=workspace)
+        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]