Optomechanically induced transparency in a PT symmetric system

Abstract

Optomechanical systems have attracted attention recently in various areas of physics, and are widely used with the purpose of laser cooling, gravitational wave detection, preparation of entangled states, cooling of mechanical mode to its ground state of motion. Some associated remarkable phenomena are optomechanically induced transparency and slow light. Here, we investigate these features in the context of parity-time (PT ) symmetry. For that purpose, we analyze a system composed of a cavity coupled to pair of PT symmetric mechanical resonators, and investigate the first-order sidebands induced by the radiation pressure on the cavity end-mirror. System is driven by a strong control field and a weak probe field. Using a perturbative method in resolved sideband regime, we observe the transmission of the probe field and slow light around the exceptional point. System exhibits different behaviors in PT broken and PT unbroken phases. In addition to these, we apply polaron transformation, and compare our results with the previous approach. Finally, we offer a preliminary exposition of phase relations for a ternary coupled PT symmetric system, where both mechanical resonators are coupled to the electromagnetic cavity which exemplifies higher-order exceptional points. Predominantly, our results highlight the effects of PT symmetry and exceptional points on the optomechanically induced transparency.