[Prototype] Efficient Graph-based Decomposition with Dijkstra's Algorithm

decomposition_demo.py

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+#!/usr/bin/env python
+# coding: utf-8
+
+# In[1]:
+
+
+import numpy as np
+import pennylane as qml
+from pennylane.ops.decompositions import DecompositionLibrary, DecompositionGraph
+
+
+# In[2]:
+
+
+library = DecompositionLibrary()
+
+
+def crx_to_rx_cz(*params, wires=None):
+    return [
+        qml.RX(params[0] / 2, wires=wires[1]),
+        qml.CZ(wires=wires),
+        qml.RX(-params[0] / 2, wires=wires[1]),
+        qml.CZ(wires=wires),
+    ]
+
+
+library.register_static_decomposition(qml.CRX, crx_to_rx_cz)
+
+
+def crx_to_rz_ry(*params, wires=None):
+    return [
+        qml.RZ(np.pi / 2, wires=wires[1]),
+        qml.RY(params[0] / 2, wires=wires[1]),
+        qml.CNOT(wires=wires),
+        qml.RY(-params[0] / 2, wires=wires[1]),
+        qml.CNOT(wires=wires),
+        qml.RZ(-np.pi / 2, wires=wires[1]),
+    ]
+
+
+library.register_static_decomposition(qml.CRX, crx_to_rz_ry)
+
+
+def crx_to_h_crz(*params, wires=None):
+    return [
+        qml.Hadamard(wires=wires[1]),
+        qml.CRZ(params[0], wires=wires),
+        qml.Hadamard(wires=wires[1]),
+    ]
+
+
+library.register_static_decomposition(qml.CRX, crx_to_h_crz)
+
+
+def crz_to_rz_cnot(*params, wires=None):
+    return [
+        qml.RZ(params[0] / 2, wires=wires[1]),
+        qml.CNOT(wires=wires),
+        qml.RZ(-params[0] / 2, wires=wires[1]),
+        qml.CNOT(wires=wires),
+    ]
+
+
+library.register_static_decomposition(qml.CRZ, crz_to_rz_cnot)
+
+
+def hadamard_to_rx_rz(*params, wires=None):
+    return [
+        qml.RZ(np.pi / 2, wires=wires),
+        qml.RX(np.pi / 2, wires=wires),
+        qml.RZ(np.pi / 2, wires=wires),
+    ]
+
+
+library.register_static_decomposition(qml.Hadamard, hadamard_to_rx_rz)
+
+
+def cnot_to_cz_h(*params, wires=None):
+    return [
+        qml.Hadamard(wires=wires[1]),
+        qml.CZ(wires=wires),
+        qml.Hadamard(wires=wires[1]),
+    ]
+
+
+library.register_static_decomposition(qml.CNOT, cnot_to_cz_h)
+
+
+def cz_to_cnot_h(*params, wires=None):
+    return [
+        qml.Hadamard(wires=wires[1]),
+        qml.CNOT(wires=wires),
+        qml.Hadamard(wires=wires[1]),
+    ]
+
+
+library.register_static_decomposition(qml.CZ, cz_to_cnot_h)
+
+
+# In[6]:
+
+
+circuit_operations = [qml.CRX(0.5, wires=[0, 1])]
+supported_operations = {"RZ", "RX", "CZ", "Hadamard"}
+
+graph = DecompositionGraph(circuit_operations, supported_operations, library)
+graph.solve(lazy=False)
+graph.decompose(circuit_operations[0])