Conditional and unconditional Gaussian quantum dynamics

Understand

This article focuses on the general theory of open quantum systems in the Gaussian regime and explores a number of diverse ramifications and consequences of the theory.

• We shall first introduce the Gaussian framework in its full generality, including a classification of Gaussian (also known as "general-dyne") quantum measurements.
• In doing so, we will give a compact proof for the parametrisation of the most general Gaussian completely positive map, which we believe to be missing in the existing literature.
• We will then move on to consider the linear coupling with a white noise bath, and derive the diffusion equations that describe the evolution of Gaussian states under such circumstances.