Perturbation approach for computing frequency- and time-resolved photon correlation functions

TL;DR

This paper introduces an algebraic perturbation method to compute frequency- and time-resolved photon correlations more efficiently, providing clearer physical insights and independence from small coupling parameters.

Contribution

It presents a novel algebraic expansion approach that simplifies photon correlation calculations and offers physical interpretation at different time scales.

Findings

Method agrees with previous formulations on a vibronic dimer model

Provides physical insights into photon correlation processes

Ensures independence from small coupling parameter 

Abstract

We propose an alternative formulation of the sensor method presented in [Phys. Rev. Lett 109, 183601 (2012)] for the calculation of frequency-filtered and time-resolved photon correlations. Our approach is based on an algebraic expansion of the joint steady state of quantum emitter and sensors with respect to the emitter-sensor coupling parameter \epsilon. This allows us to express photon correlations in terms of the open quantum dynamics of the emitting system only and ensures that computation of correlations are independent on the choice of a small value of \epsilon. Moreover, using time-dependent perturbation theory, we are able to express the frequency- and time- resolved second-order photon correlation as the addition of three components, each of which gives insight into the physical processes dominating the correlation at different time scales. We consider a bio-inspired vibronic dimer model to illustrate the agreement between the original formulation and our approach.