# cirq.PhaseFlipChannel¶

class cirq.PhaseFlipChannel(p)[source]

Probabilistically flip the sign of the phase of a qubit.

__init__(p) → None[source]

The phase flip channel.

Construct a channel to flip the phase with probability p.

This channel evolves a density matrix via:

\rho -> M_0 \rho M_0^\dagger + M_1 \rho M_1^\dagger


With:

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

Parameters: p – the probability of a phase flip. ValueError – if p is not a valid probability.

Methods

 on(*qubits) Returns an application of this gate to the given qubits. validate_args(qubits) Checks if this gate can be applied to the given qubits.