Add a supported_gates function

circuit_knitting/cutting/__init__.py

@@ -56,6 +56,7 @@
 
     qpd.generate_qpd_samples
     qpd.decompose_qpd_instructions
+    qpd.supported_gates
 
 CutQC
 =====

circuit_knitting/cutting/qpd/__init__.py

@@ -17,6 +17,7 @@
     decompose_qpd_instructions,
     WeightType,
     qpdbasis_from_gate,
+    supported_gates,
 )
 from .instructions import (
     BaseQPDGate,
@@ -29,6 +30,7 @@
     "qpdbasis_from_gate",
     "generate_qpd_samples",
     "decompose_qpd_instructions",
+    "supported_gates",
     "QPDBasis",
     "BaseQPDGate",
     "TwoQubitQPDGate",

circuit_knitting/cutting/qpd/qpd.py

@@ -215,6 +215,16 @@ def qpdbasis_from_gate(gate: Gate) -> QPDBasis:
         return f(gate)
 
 
+def supported_gates() -> set[str]:
+    """
+    Return a set of gate names supported for automatic decomposition.
+
+    Returns:
+        Set of gate names supported for automatic decomposition.
+    """
+    return set(_qpdbasis_from_gate_funcs)
+
+
 @_register_qpdbasis_from_gate("rxx", "ryy", "rzz", "crx", "cry", "crz")
 def _(gate: RXXGate | RYYGate | RZZGate | CRXGate | CRYGate | CRZGate):
     # Constructing a virtual two-qubit gate by sampling single-qubit operations - Mitarai et al

releasenotes/notes/supported-gates-d2156f58bc07fc7a.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    Addition of :func:`~circuit_knitting.cutting.qpd.supported_gates` function, which returns the names of all gates which may be automatically decomposed using :func:`~circuit_knitting.cutting.qpd.qpdbasis_from_gate`.

test/cutting/qpd/test_qpd.py

@@ -279,3 +279,7 @@ def test_qpdbasis_from_gate_unique_maps(
         ]
         assert len(unique_by_eq(a for (a, b) in relevant_maps)) == q0_num_unique
         assert len(unique_by_eq(b for (a, b) in relevant_maps)) == q1_num_unique
+
+    def test_supported_gates(self):
+        gates = supported_gates()
+        self.assertEqual({"rxx", "ryy", "rzz", "crx", "cry", "crz", "cx", "cz"}, gates)