Quantum signatures in quadratic optomechanical heat engine with an atom in a tapered trap

We investigate how quantum signatures can emerge in a single atom heat engine consisting of an atom confined in a tapered trap and subject to hot and cold thermal reservoirs. A similar system was realized experimentally in Ref.[1]. We model such a system using a quadratic optomechanical model and identify an effective Otto cycle in the system's dynamics. We compare the engine's performance in the quantum and classical regimes by evaluating the power dissipated. We find that lowering the temperature is insufficient to make the single atom engine of Ref.[1] a genuine quantum-enhanced heat engine. We show that it is necessary to make the trap more asymmetric and confined to ensure that quantum correlations cause an enhancement in the power output.