cirq.DepolarizingChannel

class cirq.DepolarizingChannel(p)

A channel that depolarizes a qubit.

__init__(p) → None

The symmetric depolarizing channel.

This channel applies one of four disjoint possibilities: nothing (the

identity channel) or one of the three pauli gates. The disjoint

probabilities of the three gates are all the same, p / 3, and the

identity is done with probability 1 - p. The supplied probability

must be a valid probability or else this constructor will raise a

ValueError.

This channel evolves a density matrix via

\rho -> (1 - p) \rho

+ (p / 3) X \rho X + (p / 3) Y \rho Y + (p / 3) Z \rho Z

Parameters:p – The probability that one of the Pauli gates is applied. Each of the Pauli gates is applied independently with probability p / 3. Raises: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.