Merge branch 'master' into stabilizers

tests/test_quantum_info_clifford.py

@@ -62,13 +62,14 @@ def test_clifford_from_circuit(backend, measurement):
         backend.assert_allclose(obj.probabilities(), result.probabilities())
 
 
+@pytest.mark.parametrize("seed", [1, 10])
 @pytest.mark.parametrize("algorithm", ["AG04", "BM20"])
 @pytest.mark.parametrize("nqubits", [1, 2, 3, 10, 50])
-def test_clifford_to_circuit(backend, nqubits, algorithm):
+def test_clifford_to_circuit(backend, nqubits, algorithm, seed):
     if backend.__class__.__name__ == "TensorflowBackend":
         pytest.skip("CliffordBackend not defined for Tensorflow engine.")
 
-    clifford = random_clifford(nqubits, backend=backend)
+    clifford = random_clifford(nqubits, seed=seed, backend=backend)
 
     symplectic_matrix_original = Clifford.from_circuit(
         clifford, engine=backend

tests/test_quantum_info_quantum_networks.py

@@ -28,6 +28,13 @@ def test_errors(backend):
     matrix = random_density_matrix(2**3, backend=backend)
     net = QuantumNetwork(matrix, (2,) * 3, backend=backend)
 
+    comb_partition = (2,) * 4
+    comb_sys_out = (False, True) * 2
+    comb = random_density_matrix(2**4, backend=backend)
+    comb_choi = QuantumNetwork(
+        comb, comb_partition, system_output=comb_sys_out, backend=backend
+    )
+
     with pytest.raises(TypeError):
         QuantumNetwork(channel.to_choi(backend=backend), partition=True)
 
@@ -91,6 +98,18 @@ def test_errors(backend):
     with pytest.raises(NotImplementedError):
         net @ network
 
+    with pytest.raises(ValueError):
+        network @ net
+
+    with pytest.raises(ValueError):
+        network @ QuantumNetwork(comb, (16, 16), pure=True, backend=backend)
+
+    with pytest.raises(ValueError):
+        comb_choi @ QuantumNetwork(comb, (16, 16), pure=True, backend=backend)
+
+    with pytest.raises(ValueError):
+        comb_choi @ net
+
     with pytest.raises(ValueError):
         QuantumNetwork(matrix, (1, 2), backend=backend)