def get_default_noise_dict():
"""Returns the current noise parameters"""
default_noise_dict = {
'X': ops.depolarize(1e-3),
'Y': ops.depolarize(1e-3),
'MS': ops.depolarize(1e-2),
'crosstalk': 0.03
}
return default_noise_dict
def _apply_depol_noise(pauli_error, moments, system_qubits):
_sq_inds = np.arange(4)
pauli_inds = np.array(list(product(_sq_inds, repeat=1)))
num_inds = len(pauli_inds)
p_other = pauli_error / (num_inds - 1) # probability of X, Y, Z gates
moments.append(ops.Moment(ops.depolarize(p_other)(q) for q in system_qubits))
def build_noise_models(self) -> List['cirq.NoiseModel']:
noise_models: List['cirq.NoiseModel'] = []
if self.t1_ns:
noise_models.append(
devices.ThermalNoiseModel(
set(self.t1_ns.keys()),
self.gate_times_ns,
cool_rate_GHz={q: 1 / T1
for q, T1 in self.t1_ns.items()},
dephase_rate_GHz={
q: 1 / Tp
for q, Tp in self.tphi_ns.items()
},
))
depolarizing_error = self._depolarizing_error
added_pauli_errors = {
op_id: ops.depolarize(p_error, len(op_id.qubits)).on(*op_id.qubits)
for op_id, p_error in depolarizing_error.items() if p_error > 0
}
# This adds per-qubit pauli error after ops on those qubits.
noise_models.append(
devices.InsertionNoiseModel(ops_added=added_pauli_errors))
# This adds per-qubit measurement error BEFORE measurement on those qubits.
if self.readout_errors:
added_measure_errors: Dict[noise_utils.OpIdentifier,
'cirq.Operation'] = {}
for qubit in self.readout_errors:
p_00, p_11 = self.readout_errors[qubit]
p = p_11 / (p_00 + p_11)
gamma = p_11 / p
added_measure_errors[noise_utils.OpIdentifier(
ops.MeasurementGate,
qubit)] = ops.generalized_amplitude_damp(p,
gamma).on(qubit)
noise_models.append(
devices.InsertionNoiseModel(ops_added=added_measure_errors,
prepend=True))
return noise_models