def noisy_moment(self, moment: 'cirq.Moment',
system_qubits: Sequence['cirq.Qid']):
if (_homogeneous_moment_is_measurements(moment)
or self.is_virtual_moment(moment)):
return moment
else:
gated_qubits = [
q for q in system_qubits if moment.operates_on_single_qubit(q)
]
return [
moment,
ops.Moment(
ops.DepolarizingChannel(self.depol_prob_map[q])(q)
for q in gated_qubits)
]
def __init__(
self,
depol_prob: float,
bitflip_prob: float,
decay_prob: float,
):
"""A depolarizing noise model with damped readout error.
Args:
depol_prob: Depolarizing probability.
bitflip_prob: Probability of a bit-flip during measurement.
decay_prob: Probability of T1 decay during measurement.
Bitflip noise is applied first, then amplitude decay.
"""
value.validate_probability(depol_prob, 'depol prob')
value.validate_probability(bitflip_prob, 'bitflip prob')
value.validate_probability(decay_prob, 'decay_prob')
self.qubit_noise_gate = ops.DepolarizingChannel(depol_prob)
self.readout_noise_gate = ops.BitFlipChannel(bitflip_prob)
self.readout_decay_gate = ops.AmplitudeDampingChannel(decay_prob)