🐛 Fix native gates handling for mirror circuits

src/mqt/bench/benchmark_generation.py

@@ -75,20 +75,26 @@ def _get_circuit(
     return qc
 
 
-def _create_mirror_circuit(qc_original: QuantumCircuit, inplace: bool = False) -> QuantumCircuit:
+def _create_mirror_circuit(
+    qc_original: QuantumCircuit, inplace: bool = False, target: Target | None = None, optimization_level: int = 0
+) -> QuantumCircuit:
     """Generates the mirror version (qc @ qc.inverse()) of a given quantum circuit.
 
     For circuits with an initial layout (e.g., mapped circuits), this function ensures
     that the final layout of the mirrored circuit matches the initial layout of the
     original circuit. While Qiskit's `inverse()` and `compose()` methods correctly track
     the permutation of qubits, this benchmark requires that the final qubit permutation
     is identical to the initial one, necessitating the explicit layout handling herein.
+    Also ensures that the mirrored circuit respect the native gate set of the target device
+    if a list of basis_gates is provided.
 
     All qubits are measured at the end of the mirror circuit.
 
     Args:
         qc_original: The quantum circuit to mirror.
         inplace: If True, modifies the circuit in place. Otherwise, returns a new circuit.
+        target: List of native gates of the target device.
+        optimization_level: Optimization level of the device.
 
     Returns:
         The mirrored quantum circuit.
@@ -107,6 +113,10 @@ def _create_mirror_circuit(qc_original: QuantumCircuit, inplace: bool = False) -
     # Form the mirror circuit by composing the original circuit with its inverse.
     target_qc.compose(qc_inv, inplace=True)
 
+    # Transpile to ensure the final circuit uses only native gates
+    if target is not None:
+        target_qc = transpile(target_qc, target=target, optimization_level=optimization_level, routing_method=None)
+
     # Add final measurements to all active qubits
     target_qc.barrier(active_qubits)
     new_creg = ClassicalRegister(len(active_qubits), "meas")