qml.transforms.remove_barrier

remove_barrier(tape)

Quantum function transform to remove Barrier gates.

Parameters

qfunc (function) – A quantum function.

Returns

the transformed quantum function

Return type

function

Example

Consider the following quantum function:

def qfunc(x, y):
    qml.Hadamard(wires=0)
    qml.Hadamard(wires=1)
    qml.Barrier(wires=[0,1])
    qml.PauliX(wires=0)
    return qml.expval(qml.PauliZ(0))

The circuit before optimization:

>>> dev = qml.device('default.qubit', wires=2)
>>> qnode = qml.QNode(qfunc, dev)
>>> print(qml.draw(qnode)(1, 2))
    0: ──H──╭||──X──┤ ⟨Z⟩
    1: ──H──╰||─────┤

We can remove the Barrier by running the remove_barrier transform:

>>> optimized_qfunc = remove_barrier(qfunc)
>>> optimized_qnode = qml.QNode(optimized_qfunc, dev)
>>> print(qml.draw(optimized_qnode)(1, 2))
   0: ──H──X──┤ ⟨Z⟩
   1: ──H─────┤

code/api/pennylane.transforms.remove_barrier

 

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