Noise Spectroscopy of Cavity Polaritons

Advancements in experimental techniques at the nanoscale have given rise to the field of molecular polaritonics. While most experiments focus on optical measurements of many-molecule samples in a cavity, recent work has reported simultaneous measurements of electron current and photon flux in polaritonic systems. Similar to past developments in molecular electronics, the logical next step is measurement of transport characteristics beyond fluxes. Here, our recent theoretical formulation of nonlinear spectroscopy of cavity polaritons [Physical Review Research 2025, 7, 033248] is extended to simulate both the current and the noise. To do so, the full counting statistics (FCS) for the pseudoparticle nonequilibrium Green's function (PP-NEGF) is formulated and applied to study fluxes, noise, and Fano factors in molecular polaritonic systems. The theoretical formulation is illustrated with numerical examples performed within a generic junction model.