fix

Author: sbrandhsn

qiskit/providers/fake_provider/generic_backend_v2.py

@@ -388,6 +388,11 @@ def _build_generic_target(self):
                 defaults = self._generate_calibration_defaults()
                 calibration_inst_map = defaults.instruction_schedule_map
 
+        is_fully_connected = (
+            self._coupling_map.graph.num_edges()
+            == self._coupling_map.graph.num_nodes() * (self._coupling_map.graph.num_nodes() - 1)
+        )
+
         # Iterate over gates, generate noise params from defaults,
         # and add instructions, noise and calibrations to target.
         for name in self._basis_gates:
@@ -406,9 +411,12 @@ def _build_generic_target(self):
                 noise_params = self._get_noise_defaults(name, gate.num_qubits)
                 self._add_noisy_instruction_to_target(gate, noise_params, calibration_inst_map)
             else:
-                qarg_set = self._coupling_map if gate.num_qubits > 1 else range(self.num_qubits)
-                props = {(qarg,) if isinstance(qarg, int) else qarg: None for qarg in qarg_set}
-                self._target.add_instruction(gate, properties=props, name=name)
+                if is_fully_connected:
+                    self._target.add_instruction(gate, properties=None, name=name)
+                else:
+                    qarg_set = self._coupling_map if gate.num_qubits > 1 else range(self.num_qubits)
+                    props = {(qarg,) if isinstance(qarg, int) else qarg: None for qarg in qarg_set}
+                    self._target.add_instruction(gate, properties=props, name=name)
 
         if self._control_flow:
             self._target.add_instruction(IfElseOp, name="if_else")

test/python/providers/fake_provider/test_generic_backend_v2.py

@@ -73,6 +73,20 @@ def test_no_noise(self):
         self.assertTrue(Operator.from_circuit(qc_res).equiv(qc))
         self.assertEqual(backend.target.qubit_properties, None)
 
+    def test_no_noise_fully_connected(self):
+        """Test no noise info when parameter is false"""
+        backend = GenericBackendV2(num_qubits=5, noise_info=False)
+        qc = QuantumCircuit(5)
+        qc.h(0)
+        qc.cx(0, 1)
+        qc.cx(0, 2)
+        qc.cx(1, 4)
+        qc.cx(3, 0)
+        qc.cx(2, 4)
+        qc_res = generate_preset_pass_manager(optimization_level=2, backend=backend).run(qc)
+        self.assertTrue(Operator.from_circuit(qc_res).equiv(qc))
+        self.assertEqual(backend.target.qubit_properties, None)
+
     def test_no_info(self):
         """Test no noise info when parameter is false"""
         backend = GenericBackendV2(