Masson Stuart J, Ferrier-Barbut Igor, Orozco Luis A, Browaeys Antoine, Asenjo-Garcia Ana
Department of Physics, Columbia University, New York, New York 10027, USA.
Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127 Paris, France.
Phys Rev Lett. 2020 Dec 31;125(26):263601. doi: 10.1103/PhysRevLett.125.263601.
Fully inverted atoms placed at exactly the same location synchronize as they deexcite, and light is emitted in a burst (known as "Dicke's superradiance"). We investigate the role of finite interatomic separation on correlated decay in mesoscopic chains and provide an understanding in terms of collective jump operators. We show that the superradiant burst survives at small distances, despite Hamiltonian dipole-dipole interactions. However, for larger separations, competition between different jump operators leads to dephasing, suppressing superradiance. Collective effects are still significant for arrays with lattice constants of the order of a wavelength, and lead to a photon emission rate that decays nonexponentially in time. We calculate the two-photon correlation function and demonstrate that emission is correlated and directional, as well as sensitive to small changes in the interatomic distance. These features can be measured in current experimental setups, and are robust to realistic imperfections.
处于完全相同位置的完全反转原子在去激发时会同步，并且会以脉冲形式发射光（称为“迪克超辐射”）。我们研究了有限原子间距在介观链中关联衰变中的作用，并通过集体跃迁算符给出了解释。我们表明，尽管存在哈密顿偶极 - 偶极相互作用，但超辐射脉冲在小距离时仍然存在。然而，对于较大的间距，不同跃迁算符之间的竞争会导致退相，从而抑制超辐射。对于晶格常数约为波长量级的阵列，集体效应仍然很显著，并导致光子发射率随时间呈非指数衰减。我们计算了双光子关联函数，并证明发射是相关且定向的，并且对原子间距的微小变化敏感。这些特征可以在当前的实验装置中进行测量，并且对实际的不完美情况具有鲁棒性。
