class cirq.PhaseDampingChannel(gamma)[source]

Dampen qubit phase.

This channel models phase damping which is the loss of quantum
information without the loss of energy.
__init__(gamma) → None[source]

The phase damping channel.

Construct a channel that enacts a phase damping constant gamma.

This channel evolves a density matrix via:
\rho -> M_0 \rho M_0^\dagger + M_1 \rho M_1^\dagger


M_0 = \begin{bmatrix}
        1 & 0 \\
        0 & \sqrt{1 - \gamma}
M_1 = \begin{bmatrix}
        0 & 0 \\
        0 & \sqrt{\gamma}
Parameters:gamma – The damping constant.
Raises:ValueError – if gamma 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.