Thermal production, protection, and heat exchange of quantum coherences

Abstract

We consider finite-sized atomic systems with varying number of particles which have dipolar interactions among them and are also under the collective driving and dissipative effect of a thermal photon environment. Focusing on the simple case of two atoms, we investigate the impact of different parameters of the model on the coherence contained in the system. We observe that, even though the system is initialized in a completely incoherent state, it evolves to a state with a finite amount of coherence and preserves that coherence in the long-time limit in the presence of thermal photons. We propose a scheme to utilize the created coherence in order to change the thermal state of a single two-level atom by having it repeatedly interact with a coherent atomic beam. Finally, we discuss the scaling of coherence as a function of the number of particles in our system up to N = 7.