General Non-Markovian structure of Gaussian Master and Stochastic Schr\"odinger Equations

TL;DR

This paper demonstrates that Gaussian non-Markovian open quantum systems can be analyzed with a structure similar to Markovian systems, providing new parametrizations and unravellings for their master equations.

Contribution

It introduces a tractable framework for Gaussian non-Markovian dynamics, generalizing the Lindblad structure and extending stochastic Schrödinger equations to non-Markovian cases.

Findings

Gaussian non-Markovian dynamics are structurally similar to Markovian cases.

The class of stochastic Schrödinger equations is extended to non-Markovian systems.

Known non-Markovian unravellings are special cases of the new class.

Abstract

General open quantum systems display memory features, their master equations are non-Markovian. We show that the subclass of Gaussian non-Markovian open system dynamics is tractable in a depth similar to the Markovian class. The structure of master equations exhibits a transparent generalization of the Lindblad structure. We find and parametrize the class of stochastic Schr\"odinger equations that unravel a given master equation, such class was before known for Markovian systems only. We show that particular non-Markovian unravellings known in the literature are special cases of our class.