arXiv:1709.08327 · Physical Review A
Dissipative preparation of steady Greenberger-Horne-Zeilinger states for Rydberg atoms with quantum Zeno dynamics
Xiao‐Qiang Shao, Jin-Hui Wu, X. X. Yi, Gui‐Lu Long
Abstract
Inspired by a recent work [F. Reiter, D. Reeb, and A. S. S\o{}rensen, Phys. Rev. Lett. 117, 040501 (2016)], we present a simplified proposal for dissipatively preparing a Greenberger-Horne-Zeilinger (GHZ) state of three Rydberg atoms in a cavity. The $Z$ pumping is implemented under the action of the spontaneous emission of $\mathrm{\ensuremath{\Lambda}}$-type atoms and the quantum Zeno dynamics induced by strong continuous coupling. In the meantime, a dissipative Rydberg pumping breaks up the stability of the state $|{\mathrm{GHZ}}_{+}\ensuremath{\rangle}$ in the process of $Z$ pumping, making $|{\mathrm{GHZ}}_{\ensuremath{-}}\ensuremath{\rangle}$ the unique steady state of the system. Compared with the former scheme, the number of driving fields acting on atoms is greatly reduced and only a single-mode cavity is required. The numerical simulation of the full master equation reveals that a high fidelity $\ensuremath{\sim}98%$ can be obtained with the currently achievable parameters in the Rydberg-atom-cavity system.