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


M_0 = \sqrt{p} \begin{bmatrix}
                    1 & 0  \\
                    0 & 1
M_1 = \sqrt{1-p} \begin{bmatrix}
                    1 & 0 \\
                    0 & -1
Parameters:p – the probability of a phase flip.
Raises:ValueError – if p is not a valid probability.


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.