toqito.matrices.gen_pauli

Produces the generalized Pauli operator matrices.

Module Contents

toqito.matrices.gen_pauli.gen_pauli(k_1, k_2, dim)[source]

Produce generalized Pauli operator [@WikiPauliGen].

Generates a dim-by-dim unitary operator. More specifically, it is the operator (X^k_1 Z^k_2), where (X) and (Z) are the “gen_pauli_x” and “gen_pauli_z” operators that naturally generalize the Pauli X and Z operators. These matrices span the entire space of dim-by-dim matrices as k_1 and k_2 range from 0 to dim-1, inclusive.

Note that the generalized Pauli operators are also known by the name of “discrete Weyl operators”. (Lecture 6: Further Remarks On Measurements And Channels from [@Watrous_2011_Lecture_Notes])

Examples

The generalized Pauli operator for k_1 = 1, k_2 = 0, and dim = 2 is given as the standard Pauli-X matrix

[
G_{1, 0, 2} = begin{pmatrix}

0 & 1 \ 1 & 0

end{pmatrix}.

]

This can be obtained in |toqito⟩ as follows.

```python exec=”1” source=”above” from toqito.matrices import gen_pauli

print(gen_pauli(k_1=1, k_2=0, dim=2)) ```

The generalized Pauli matrix k_1 = 1, k_2 = 1, and dim = 2 is given as the standard Pauli-Y matrix

[
G_{1, 1, 2} = begin{pmatrix}

0 & -1 \ 1 & 0

end{pmatrix}.

]

This can be obtained in |toqito⟩ as follows.

```python exec=”1” source=”above” from toqito.matrices import gen_pauli

print(gen_pauli(k_1=1, k_2=1, dim=2)) ```

Parameters:
  • k_1 (int) – (a non-negative integer from 0 to dim-1 inclusive).

  • k_2 (int) – (a non-negative integer from 0 to dim-1 inclusive).

  • dim (int) – (a positive integer indicating the dimension).

Returns:

A generalized Pauli operator.

Return type:

numpy.ndarray