Add clifford gates to collect_cliffords (#12750)

* add clifford gates to collect_cliffords

* replace hard coded clifford names by clifford_circuit names

* move import

* replace hard coded clifford names in random_clifford_circuit

* add release notes

* add permutation to collect_clifford gate list

qiskit/circuit/random/utils.py

@@ -18,6 +18,7 @@ from qiskit.circuit import ClassicalRegister, QuantumCircuit, CircuitInstruction
 from qiskit.circuit import Reset
 from qiskit.circuit.library import standard_gates
 from qiskit.circuit.exceptions import CircuitError
+from qiskit.quantum_info.operators.symplectic.clifford_circuits import _BASIS_1Q, _BASIS_2Q
 
 
 def random_circuit(
@@ -312,8 +313,9 @@ def random_clifford_circuit(num_qubits, num_gates, gates="all", seed=None):
         QuantumCircuit: constructed circuit
     """
 
-    gates_1q = ["i", "x", "y", "z", "h", "s", "sdg", "sx", "sxdg"]
-    gates_2q = ["cx", "cz", "cy", "swap", "iswap", "ecr", "dcx"]
+    gates_1q = list(set(_BASIS_1Q.keys()) - {"v", "w", "id", "iden", "sinv"})
+    gates_2q = list(_BASIS_2Q.keys())
+
     if gates == "all":
         if num_qubits == 1:
             gates = gates_1q

qiskit/transpiler/passes/optimization/collect_cliffords.py

@@ -22,6 +22,7 @@ from qiskit.transpiler.passes.optimization.collect_and_collapse import (
 )
 
 from qiskit.quantum_info.operators import Clifford
+from qiskit.quantum_info.operators.symplectic.clifford_circuits import _BASIS_1Q, _BASIS_2Q
 
 
 class CollectCliffords(CollectAndCollapse):
@@ -69,21 +70,11 @@ class CollectCliffords(CollectAndCollapse):
         )
 
 
-clifford_gate_names = [
-    "x",
-    "y",
-    "z",
-    "h",
-    "s",
-    "sdg",
-    "cx",
-    "cy",
-    "cz",
-    "swap",
-    "clifford",
-    "linear_function",
-    "pauli",
-]
+clifford_gate_names = (
+    list(_BASIS_1Q.keys())
+    + list(_BASIS_2Q.keys())
+    + ["clifford", "linear_function", "pauli", "permutation"]
+)
 
 
 def _is_clifford_gate(node):

releasenotes/notes/fix-collect-clifford-83af26d98b8c69e8.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Add more Clifford gates to the :class:`.CollectCliffords()` transpiler pass.
+    In particular, we have added the gates :class:`ECRGate()`, :class:`DCXGate()`,
+    :class:`iSWAPGate()`, :class:`SXGate()` and :class:`SXdgGate()` to this transpiler pass.