Background Noise Processes

For each subsystem (slot in the register), you also specify what background processes and noise parameters describe it. For instance, it could be a T1Decay or T2Dephasing process, or a coherent error, or a non-Markovian bath. It is supported by all backends (but maybe with twirling, e.g. to support T1Decay in a Clifford simulation).

Currently we implement:

AmplitudeDamping	A depolarization background.
Depolarization	A depolarization background. The `τ` parameter specifies the average time between depolarization events (assuming a Poisson point process). I.e. after time `t` the probability for an depolarization event is `1-exp(-t/τ)`.
PauliNoise	A Pauli noise background.
T1Decay	A background describing the T₁ decay of a two-level system.
T2Dephasing	A background describing the T₂ dephasing of a two-level system.

If you want to introspect these noise processes, you can use the paulinoise, krausops, and lindbladop functions.