qml.template

template(func)

Register a quantum template with PennyLane.

This decorator wraps the given function and makes it return a list of all queued Operations.

Example:

When defining a template, simply decorate the template function with this decorator.

@qml.template
def bell_state_preparation(wires):
    qml.Hadamard(wires=wires[0])
    qml.CNOT(wires=wires)

This registers the template with PennyLane, making it compatible with functions that act on templates, such as pennylane.inv():

dev = qml.device('default.qubit', wires=2)

@qml.qnode(dev)
def circuit():
    qml.inv(bell_state_preparation(wires=[0, 1]))
    return qml.expval(qml.PauliZ(0) @ qml.PauliZ(1))

Parameters

func (callable) – A template function

Returns

The wrapper function

Return type

callable