Better and faster lindblad simulation of transmons.

[GlaserN]

Is your feature request related to a problem? Please describe. Higher levels of the transmon have not been thorougly been tested for lindblad simulation. The Lindblad simulation takes a very long tme especially for long sequences. It is therefore necessary to have a faster approximate version not involving full matrix exponentiation of the superoperator.

Describe the solution you'd like Implement how noise scales for higher levels of the transmon. Approximate faster calculation of the Lindblad propagation

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.