toqito.perms.swap_operator

Swap operator. is used to generate a unitary operator that can swap two subsystems.

Module Contents

toqito.perms.swap_operator.swap_operator(dim, is_sparse=False)

Produce a unitary operator that swaps two subsystems.

Provides the unitary operator that swaps two copies of dim-dimensional space. If the two subsystems are not of the same dimension, dim should be a 1-by-2 vector containing the dimension of the subsystems.

Examples

The (2)-dimensional swap operator is given by the following matrix

[

X_2 = begin{pmatrix}

1 & 0 & 0 & 0 \ 0 & 0 & 1 & 0 \ 0 & 1 & 0 & 0 \ 0 & 0 & 0 & 1

end{pmatrix}

]

Using |toqito⟩ we can obtain this matrix as follows.

```python exec=”1” source=”above” from toqito.perms import swap_operator

print(swap_operator(2)) ```

The (3)-dimensional operator may be obtained using |toqito⟩ as follows.

```python exec=”1” source=”above” from toqito.perms import swap_operator

print(swap_operator(3)) ```

Parameters:

• dim (list[int] | int) – The dimensions of the subsystems.

• is_sparse (bool) – Sparse if True and non-sparse if False.

Returns:

The swap operator of dimension dim.

Return type:

numpy.ndarray