qml.pow

pow(base, z=1, lazy=True, id=None)

Raise an Operator to a power.

Parameters

• base (Operator) – the operator to be raised to a power

• z (float) – the exponent (default value is 1)

Keyword Arguments

• lazy=True (bool) – In lazy mode, all operations are wrapped in a Pow class and handled later. If lazy=False, operation-specific simplifications are first attempted.

• id (str) – custom label given to an operator instance, can be useful for some applications where the instance has to be identified

Returns

Operator

Note

This operator supports a batched base, a batched coefficient and a combination of both:

>>> op = qml.pow(qml.RX([1, 2, 3], wires=0), z=4)
>>> qml.matrix(op).shape
(3, 2, 2)
>>> op = qml.pow(qml.RX(1, wires=0), z=[1, 2, 3])
>>> qml.matrix(op).shape
(3, 2, 2)
>>> op = qml.pow(qml.RX([1, 2, 3], wires=0), z=[4, 5, 6])
>>> qml.matrix(op).shape
(3, 2, 2)

But it doesn’t support batching of operators:

>>> op = qml.pow([qml.RX(1, wires=0), qml.RX(2, wires=0)], z=4)
AttributeError: 'list' object has no attribute 'name'

See also

Pow, pow().

Example

>>> qml.pow(qml.X(0), 0.5)
X(0)**0.5
>>> qml.pow(qml.X(0), 0.5, lazy=False)
SX(0)
>>> qml.pow(qml.X(0), 0.1, lazy=False)
X(0)**0.1
>>> qml.pow(qml.X(0), 2, lazy=False)
I(0)

Lazy behaviour can also be accessed via op ** z.

code/api/pennylane.pow

 

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