fix qiskit bug

Author: refraction-ray

setup.py

@@ -22,7 +22,7 @@
         "tensorflow": ["tensorflow"],
         "jax": ["jax", "jaxlib"],
         "torch": ["torch"],
-        "qiskit": ["qiskit"],
+        "qiskit": ["qiskit", "sympy", "symengine"],
         "cloud": ["qiskit", "mthree<2.8"],
     },
     classifiers=[

tensorcircuit/translation.py

@@ -13,8 +13,6 @@
 
 try:
     import qiskit.quantum_info as qi
-    import symengine
-    import sympy
     from qiskit import QuantumCircuit
     from qiskit.circuit import Parameter, ParameterExpression
     from qiskit.circuit.exceptions import CircuitError
@@ -28,6 +26,14 @@
     CircuitInstruction = Any
     QuantumCircuit = Any
 
+try:
+    import symengine
+    import sympy
+except ImportError:
+    logger.info(
+        "Please first ``pip install -U sympy symengine`` to enable `qiskit2tc` in translation module"
+    )
+
 try:
     import cirq
 except ImportError:
@@ -325,7 +331,9 @@ def qir2qiskit(
             qiskit_circ.append(gate, index_reversed)
         elif gate_name == "multicontrol":
             unitary = backend.numpy(backend.convert_to_tensor(parameters["unitary"]))
+            k = int(np.log(unitary.shape[-1]) / np.log(2) + 1e-7)
             ctrl_str = "".join(map(str, parameters["ctrl"]))[::-1]
+            unitary = perm_matrix(k) @ unitary @ perm_matrix(k)
             gate = UnitaryGate(unitary, label=qis_name).control(
                 len(ctrl_str), ctrl_state=ctrl_str
             )

tests/test_circuit.py

@@ -1094,7 +1094,7 @@ def test_qiskit2tc():
         import qiskit.quantum_info as qi
         from qiskit import QuantumCircuit
         from qiskit.circuit.library import HamiltonianGate
-        from qiskit.circuit.library.standard_gates import MCXGate, SwapGate
+        from qiskit.circuit.library.standard_gates import MCXGate, SwapGate, CXGate
 
         from tensorcircuit.translation import perm_matrix
     except ImportError:
@@ -1150,12 +1150,13 @@ def test_qiskit2tc():
     mcx_g = MCXGate(3, ctrl_state="010")
     qisc.append(mcx_g, [0, 1, 2, 3])
     qisc.ccx(0, 1, 2, ctrl_state="01")
-    CCCRX = SwapGate().control(2, ctrl_state="01")
-    qisc.append(CCCRX, [0, 1, 2, 3])
+    CCswap = SwapGate().control(2, ctrl_state="01")
+    qisc.append(CCswap, [0, 1, 2, 3])
+    CCCX = CXGate().control(2, ctrl_state="01")
+    qisc.append(CCCX, [1, 2, 3, 4])
 
-    c = tc.Circuit.from_qiskit(qisc, n, np.eye(2**n))
-    tc_unitary = c.wavefunction()
-    tc_unitary = np.reshape(tc_unitary, [2**n, 2**n])
+    c = tc.Circuit.from_qiskit(qisc, n)
+    tc_unitary = c.matrix()
     qis_unitary = qi.Operator(qisc)
     qis_unitary = np.reshape(qis_unitary, [2**n, 2**n])
     p_mat = perm_matrix(n)