Eigenstate Thermalization Hypothesis in 2D Photon Gas System

The eigenstate thermalization hypothesis states that as the size of the system increases, fluctuations of observables should decay exponentially to canonical averages. The hypothesis provides an interpretation of why isolated quantum system can equilibrate or obey thermodynamic laws. In our work, we aim to test this hypothesis by employing a two-dimensional photon gas trapped in a gravitational wedge potential. Gas takes form of an intensity pattern comprised eigenstates and captured by a camera. Photons are created via excitation of a dye inside a Fabry-Perot mirror resonator by a green (532 nm) nanosecond (26 ns) laser. By changing gain (laser pumping) position different system states are probed. Statistical and spatial properties of latter are analyzed and processed to test the hypothesis. This work demonstrates a novel photonic platform to experimentally probe thermalization in isolated quantum systems.