cirq.PhaseFlipChannel

class cirq.PhaseFlipChannel(p: float)[source]

Probabilistically flip the sign of the phase of a qubit.

__init__(p: float) → None[source]

The phase flip channel.

Construct a channel to flip the phase with probability p.

This channel evolves a density matrix via:

$$ \rho \rightarrow M_0 \rho M_0^\dagger + M_1 \rho M_1^\dagger $$
With:

$$ \begin{aligned} M_0 =& \sqrt{1 - p} \begin{bmatrix} 1 & 0 \newline 0 & 1 \end{bmatrix} \newline M_1 =& \sqrt{p} \begin{bmatrix} 1 & 0 \newline 0 & -1 \end{bmatrix} \end{aligned} $$

Parameters

p – the probability of a phase flip.

Raises

ValueError – if p is not a valid probability.