fix: update connectivity in default transpiler

qiboteam · csookim · Nov 27, 2024 · Oct 17, 2024 · Oct 22, 2024 · Oct 23, 2024
commit 2c7190eb9bf245068b520e1096482bd73c86fc79
diff --git a/src/qibo/backends/__init__.py b/src/qibo/backends/__init__.py
@@ -144,12 +144,8 @@ def _default_transpiler(cls):
             and natives is not None
             and connectivity_edges is not None
         ):
-            # only for q{i} naming
-            node_mapping = {q: i for i, q in enumerate(qubits)}
-            edges = [
-                (node_mapping[e[0]], node_mapping[e[1]]) for e in connectivity_edges
-            ]
-            connectivity = nx.Graph(edges)
+            connectivity = nx.Graph(connectivity_edges)
+            connectivity.add_nodes_from(qubits)
 
             return Passes(
                 connectivity=connectivity,

diff --git a/src/qibo/models/error_mitigation.py b/src/qibo/models/error_mitigation.py
@@ -1172,9 +1172,8 @@ def _execute_circuit(circuit, qubit_map, noise_model=None, nshots=10000, backend
     elif backend.name == "qibolab":  # pragma: no cover
         qubits = backend.qubits
         connectivity_edges = backend.connectivity
-        node_mapping = {q: i for i, q in enumerate(qubits)}
-        edges = [(node_mapping[e[0]], node_mapping[e[1]]) for e in connectivity_edges]
-        connectivity = nx.Graph(edges)
+        connectivity = nx.Graph(connectivity_edges)
+        connectivity.add_nodes_from(qubits)
         transpiler = Passes(
             connectivity=connectivity,
             passes=[Custom(initial_map=qubit_map, connectivity=connectivity)],

diff --git a/tests/test_backends_global.py b/tests/test_backends_global.py
@@ -171,8 +171,13 @@ def natives(self):
     _Global._backend = backend
     transpiler = _Global.transpiler()
 
-    assert list(transpiler.connectivity.nodes) == [0, 1, 2, 3, 4]
-    assert list(transpiler.connectivity.edges) == [(0, 1), (1, 2), (2, 3), (3, 4)]
+    assert list(transpiler.connectivity.nodes) == ["A1", "A2", "A3", "A4", "A5"]
+    assert list(transpiler.connectivity.edges) == [
+        ("A1", "A2"),
+        ("A2", "A3"),
+        ("A3", "A4"),
+        ("A4", "A5"),
+    ]
     assert (
         NativeGates.CZ in transpiler.native_gates
         and NativeGates.GPI2 in transpiler.native_gates