Ch 33.3 The most general Markovian master equation for the density matrix of an open quantum system: $\frac{d\hat{\rho}}{dt} = -\frac{i}{\hbar}[\hat{H}, \hat{\rho}] + \sum_k\left(\hat{L}_k\hat{\rho}\hat{L}_k^\dagger - \frac{1}{2}\{\hat{L}_k^\dagger\hat{L}_k, \hat{\rho}\}\right)$, where $\hat{L}_k$ a