General-dyne unravelling of a thermal master equation

Abstract

We analyse the unravelling of the quantum optical master equation at finite temperature due to direct, continuous, general-dyne detection of the environment. We first express the general-dyne Positive Operator Valued Measure (POVM) in terms of the eigenstates of a non-hermitian operator associated to the general-dyne measurement. Then, we derive the stochastic master equation obtained by considering the interaction between the system and a reservoir at thermal equilibrium, which is measured according to the POVM previously determined. Finally, we present a feasible measurement scheme which reproduces general-dyne detection for any value of the parameter characterising the stochastic master equation.

6 pages, 1 figure; v2: published version in "Russian Journal of Mathematical Physics - Special Issue dedicated to Viacheslav Belavkin"; Ref. [19] added in the arXiv version but missing in the journal version