Light Assisted Spontaneous Dimerization of Atoms in Free Space

We theoretically investigate the effects of atomic motion in subwavelength atomic arrays. In a perfect lattice, the array's radiative properties are characterized by collective resonances with larger and narrower linewidths compared to the response of a single atom. Atomic center-of-mass fluctuations modify the optical response of the system as they become correlated with the internal atomic dynamics. Here, we discuss how the dipole-mediated optomechanical forces facilitate the self-organization of atoms into an ordered configuration with subwavelength features. We study the probability of loading the atoms in these configurations and investigate the ensuing spin-motion correlations. These results advance the understanding of optomechanical effects in atomic arrays and are relevant for recent experiments on cold atoms in subwavelength lattices.