A photonic Carnot engine powered by a spin-star network. (26th April 2017)

• Record Type: Journal Article
• Authors: Türkpençe, Deniz; Altintas, Ferdi; Paternostro, Mauro; Müstecaplioğlu, Özgür E.
• Is Part Of: Europhysics letters. Volume 117:Number 5(2017:Mar.)
• Publication Date: 2017-04-26
• Subjects: 03.67.-a -- 05.70.-a -- 03.65.Yz; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/117/50002
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: We propose a spin-star network, where a central spin-(1/2), acting as a quantum fuel, is coupled to N outer spin-(1/2) particles. If the network is in thermal equilibrium with a heat bath, the central spin can have an effective temperature, higher than that of the bath, scaling nonlinearly with N . Such temperature can be tuned with the anisotropy parameter of the coupling. Using a beam of such central spins to pump a micromaser cavity, we determine the dynamics of the cavity field using a coarse-grained master equation. We find that the central-spin beam effectively acts as a hot reservoir to the cavity field and brings it to a thermal steady state whose temperature benefits from the same nonlinear enhancement with N and results in a highly efficient photonic Carnot engine. The validity of our conclusions is tested against the presence of atomic and cavity damping using a microscopic master equation method for typical microwave cavity-QED parameters. The role played by quantum coherence and correlations on the scaling effect is pointed out. An alternative scheme where the spin-(1/2) is coupled to a macroscopic spin- particle is also discussed.