Refactor to set qubit_properties when constructing target

qiskit_ibm_provider/ibm_backend.py

@@ -57,13 +57,11 @@
     IBMBackendApiError,
     IBMBackendApiProtocolError,
 )
-from .ibm_qubit_properties import IBMQubitProperties
 from .job import IBMJob, IBMCircuitJob, IBMCompositeJob
 from .utils import validate_job_tags
 from .utils.backend import convert_reservation_data
 from .utils.backend_converter import (
     convert_to_target,
-    qubit_props_dict_from_props,
 )
 from .utils.converters import local_to_utc
 from .utils.json_decoder import defaults_from_server_data, properties_from_server_data
@@ -214,7 +212,6 @@ def __init__(
         self._api_client = api_client
         self._configuration = configuration
         self._properties = None
-        self._qubit_properties: Dict[int, IBMQubitProperties] = None
         self._defaults = None
         self._target = None
         self._max_circuits = configuration.max_experiments
@@ -345,30 +342,6 @@ def target(self) -> Target:
         self._convert_to_target()
         return self._target
 
-    def qubit_properties(
-        self, qubit: Union[int, List[int]]
-    ) -> Union[IBMQubitProperties, List[IBMQubitProperties]]:
-        """Return IBMQubitProperties for a given qubit.
-
-        Args:
-            qubit: The qubit to get the
-                :class:`~qiskit_ibm_provider.IBMQubitProperties` object for. This can
-                be a single integer for 1 qubit or a list of qubits and a list
-                of :class:`~qiskit_ibm_provider.IBMQubitProperties` objects will be
-                returned in the same order
-
-        Returns:
-            IBMQubitProperties or a list of IBMQubitProperties
-        """
-        self._get_properties()
-        if not self._qubit_properties:
-            self._qubit_properties = qubit_props_dict_from_props(self._properties)
-        if isinstance(qubit, int):  # type: ignore[unreachable]
-            return self._qubit_properties.get(qubit)
-        if isinstance(qubit, List):
-            return [self._qubit_properties.get(q) for q in qubit]
-        return None
-
     def run(
         self,
         circuits: Union[

qiskit_ibm_provider/utils/backend_converter.py

@@ -12,7 +12,7 @@
 
 """Converters for migration from IBM Quantum BackendV1 to BackendV2."""
 
-from typing import Any, Dict
+from typing import Any, Dict, List
 
 from qiskit.transpiler.target import Target, InstructionProperties
 from qiskit.utils.units import apply_prefix
@@ -47,9 +47,13 @@ def convert_to_target(
         "reset": Reset(),
     }
     custom_gates = {}
-    target = Target(num_qubits=configuration.n_qubits)
+    target = None
     # Parse from properties if it exsits
     if properties is not None:
+        qubit_properties = qubit_props_list_from_props(properties=properties)
+        target = Target(
+            num_qubits=configuration.n_qubits, qubit_properties=qubit_properties
+        )
         # Parse instructions
         gates: Dict[str, Any] = {}
         for gate in properties.gates:
@@ -86,6 +90,7 @@ def convert_to_target(
         target.add_instruction(Measure(), measure_props)
     # Parse from configuration because properties doesn't exist
     else:
+        target = Target(num_qubits=configuration.n_qubits)
         for gate in configuration.gates:
             name = gate.name
             gate_props = (
@@ -129,13 +134,13 @@ def convert_to_target(
     return target
 
 
-def qubit_props_dict_from_props(
+def qubit_props_list_from_props(
     properties: BackendProperties,
-) -> Dict[int, IBMQubitProperties]:
+) -> List[IBMQubitProperties]:
     """Uses BackendProperties to construct
-    and return IBMQubitProperties class.
+    and return a list of IBMQubitProperties.
     """
-    qubit_props = {}
+    qubit_props: List[IBMQubitProperties] = []
     for qubit, _ in enumerate(properties.qubits):
         t_1 = properties.t1(qubit) * 1e-6  # microseconds to seconds
         t_2 = properties.t2(qubit) * 1e-6  # microseconds to seconds