Adding dynamical generators in quantum master equations

Understand

The quantum master equation is a widespread approach to describing open quantum system dynamics.

• In this approach, the effect of the environment on the system evolution is entirely captured by the dynamical generator, providing a compact and versatile description.
• However, care needs to be taken when several noise processes act simultaneously or the Hamiltonian evolution of the system is modified.
• Here, we show that generators can be added at the master equation level without compromising physicality only under restrictive conditions.