Techniques to slowand t rap neutral atoms at high d ensities with r adiative forces are discussed in this review article. It isshown that the radiative force on an atomic system has two components, one coming from the rnomentum transferred from the photon to the atom and the other resul ting f rom the interaction of the transi t ion d i po 1 e mo- ment with the radiation field gradient. Among several methods of laser cooling, we emphasize Zeeman tuning of the electronic l evels and fre- quency-sweeping techniques. Trapping of neutral atoms is ano ther i n- teresting subject discussed in this review. We present recent resul ts obtained in light and magnetic traps. Finally, techniques to f urther c001 atoms inside traps a re presented and the future of laser cool i ng of neutral atoms by means of radiation pressure is discussed.
The use of light presure to cool and stop neutral atoms has been an area of considerable interest recently. Cooled neutral atoms are needed for a variety of interesting experiments involving neutral atom traps and ultrahigh-resolution spectroscopy. Laser cooling of sodium has previously been demonstrated using elegant but quite elaborate apparatus.1,2 These techniques employed stabilized dye lasers and a variety of additional sophisticated hardware. We have demonstrated that the frequency chirp technique of Ref. 2 can be implemented using inexpensive diode lasers and simple electronics.
Abstract Interfacing trapped neutral atoms with light propagating in nanophotonic waveguides enables efficient and long-range photon-mediated atom–atom interactions. Here we demonstrate a hybrid nanophotonic trap for cold neutral atoms, which leverages surface forces for attraction and blue-detuned evanescent light for repulsion. We attribute the attractive potential to a combination of the Casimir–Polder interaction and electrostatic attraction due to charges on the waveguide surface. Despite the shallow depth of the trap, we load atoms into it via adiabatic transfer from a conventional two-colour dipole trap with an efficiency of 96(5)%. Notably, the hybrid trap supports a long atomic storage time of 140(9) ms. Moreover, it exhibits a Ramsey coherence time
T2∗ T 2 * = 17.8(7) ms and spin-echo coherence time
T2′ T 2 ′ = 44.7(2.5) ms, which greatly exceed previously reported values. Our results pave the way for further explorations of atom–surface interactions at the nanoscale and illustrate the potential of harnessing surface forces to enhance storage and coherence times for atoms coupled to nanophotonic waveguides. This advance offers new opportunities for neutral-atom quantum technologies.