Optical binding with cold atoms

Abstract

Optical binding is a form of light-mediated forces between elements of matter which emerge in response to the collective scattering of light. Such phenomenon has been studied mainly in the context of equilibrium stability of dielectric spheres arrays which move amid dissipative media. In this letter, we demonstrate that optically bounded states of a pair of cold atoms can exist, in the absence of non-radiative damping. We study the scaling laws for the unstable-stable phase transition at negative detuning and the unstable-metastable one for positive detuning. In addition, we show that angular momentum can lead to dynamical stabilisation with infinite range scaling. arXiv:1711.06173v2 [physics.atom-ph]

Stochastic heating and self-induced cooling in optically bound pairs of atoms

“…An important consequence pointed out in Ref. [9] is that since each atom exerts a central force on the other, the angular momentum is preserved, instead of being damped by viscous forces as for dielectrics in fluids [18]. Yet, despite the apparent simplicity of the problem -a two-dimensional two-body dynamics where both total momentum and total angular momentum are conserved -an additional effect of cooling or heating was reported, on time scales much longer than that needed for the two atoms to oscillate In this work, we investigate the coupling between the dipole dynamics and the center of mass dynamics to elucidate the slow change in temperature of the system.…”

“…In a similar fashion, it has recently been proposed to optically bind pairs of atoms confined in two dimensions by a stationary wave, where each atom remains at a multiple of the optical wavelength from the other [9]. This effect stems from the generation of a non-trivial potential * angel.tarramera@unimi.it † bachelard.romain@gmail.com landscape due to the interference between the trapping beams and the wave radiated by each atom (see Fig.1).…”

Cooperative cooling in a one-dimensional chain of optically bound cold atoms

“…In this context, only recently was the possibility of binding optically cold atoms [18] discussed. Indeed, the binding force is comparatively stronger for particles of size comparable to the optical wavelengths [16], and the smallest objects such as atoms present unstable configurations as the heating due to the random recoil overcomes the binding potential [19].…”

“…Indeed, the binding force is comparatively stronger for particles of size comparable to the optical wavelengths [16], and the smallest objects such as atoms present unstable configurations as the heating due to the random recoil overcomes the binding potential [19]. Nevertheless, differently from dielectrics, cold atoms present an atomic resonance, which leads to an extra cooling mechanism for pairs of atoms in an OB configuration [18,19]. Although this extra damping is not sufficient to reach stability for pairs of cold atoms without an additional stabilization mechanism such as molasses, it represents a further step toward this goal.…”

Towards a measurement of the Debye length in very large magneto-optical traps

“…We note that these long range forces stem from the resonant dipole-dipole coupling between atoms [20][21][22][23][24][25][26], which if interference can be neglected lead to radiation trapping of light in cold atoms [27][28][29]. This dipole-dipole coupling is also at the origin of modified radiation pressure on the center of mass [30,31] and of optical binding with cold atoms [32] as well as of super-subradiance [33][34][35].…”