Function PGate 

pub fn PGate(radix: usize) -> UnitaryExpression

The single-qudit phase gate.

The common qubit phase gate is given by the following matrix:

$$ \begin{pmatrix} 1 & 0 \\ 0 & \exp({i\theta}) \\ \end{pmatrix} $$

The qutrit phase gate has two parameterized relative phases:

$$ \begin{pmatrix} 1 & 0 & 0 \\ 0 & \exp({i\theta_0}) & 0 \\ 0 & 0 & \exp({i\theta_1}) \\ \end{pmatrix} $$

The d-level phase gate has d-1 parameterized relative phases. This gate is Clifford iff all of the relative phases are powers of roots of unity.

References:

• https://www.nature.com/articles/s41467-022-34851-z
• https://arxiv.org/pdf/2204.13681.pdf