Beyond Maxwell-Boltzmann statistics using confined vapor cells

Coherence time of thermal photons in rubidium vapor cells with varying thicknesses, reveal that there is clear dependence of the photon correlation time on cell thickness. Standard theoretical models accurately predict the coherence time in centimeter-scale cells. In this study we demonstrated, that these models break down in micrometer and sub-micrometer regimes. Cell sizes ranging from mm-scale down to 200 nm did not adhere to prediction based on the standard models. In order to address this shortcoming, we develop an alternative approach better suited for estimating photonic coherence times in ultra-thin vapor cells. This work, highlights the need for a modified theoretical treatment of the coherence time in the nanoscale regime.