| Open quantum systems compared to closed quantum systems can not use the wavefunction to describe the interaction of the system and the surrounding environment, becausethe system state with the surrounding environment is entangled. Therefore, for an openquantum system, we use the density matrix to describe the system state. This article usesstochastic master equation analysis method to study the cavity field detection system, toimprove the signal to noise ratio of the homodyne detection, we use balanced homodynedetection method to probe the cavity field system. With the detecting cavity field system, theevolution of the density matrix is derived, and we further present a derivation of stochasticmaster equation determine the time evolution of the general quantum systems. Finally, themaster equation is applied to the quantum system, and could obtained the transitionprobabilities of the quantum system. |
