Atomic-scale optical tweezer: how to manipulate single atoms

Axel Kuhn

Matthew A. Norcia, Aaron W. Young, Adam M. Kaufman

Optical tweezers provide a versatile platform for the manipulation and detection of single atoms.Here, we use optical tweezers to demonstrate a set of tools for the microscopic control of atomic strontium, which has two valence electrons.Compared to the single-valence-electron atoms typically used with tweezers, strontium has a more complex internal state structure with a variety of transition wavelengths and linewidths.We report single-atom loading into an array of subwavelength scale optical tweezers and lightshift-free control of a narrow-linewidth optical transition.We use this transition to perform threedimensional ground-state cooling and to enable high-fidelity nondestructive imaging of single atoms on subwavelength spatial scales.These capabilities, combined with the rich internal structure of strontium, open new possibilities including tweezer-based metrology, new quantum computing architectures, and new paths to low-entropy many-body physics.

Yichao Yu, Lee R. Liu, Kenneth Wang +4 more

K.Y. Kim, Kangheun Kim, Jaewook Ahn

ABSTRACT We introduce and experimentally demonstrate an energy‐efficient method for holding and rearranging an array of atoms using only optical tweezers. Our approach employs a single optical tweezer that sequentially releases and recaptures individual atoms. By applying a stroboscopic harmonic potential, we maintain the phase‐space quadrature of each atom's probability distribution during this “blinking” process, provided the trap frequency meets specific conditions. In our proof‐of‐concept experiments, we show that a blinking tweezer can hold atoms using just of the optical power per atom and further facilitate rearrangement atoms in various configurations. With further technical improvements, such as ground‐state cooling and correction for trap anharmonicities, this technique is expected to be scaled up to around atoms in our setup. This method provides a scalable and reconfigurable platform for optical tweezer arrays, with potential applications in assembling and manipulating large‐scale quantum systems.

Junmin Wang, Jun He, Baodong Yang +2 more

Single cesium atom prepared in a large-magnetic-gradient magneto-optical trap (MOT) has been efficiently loaded into a microscopic far-off-resonance optical trap (FORT, or optical tweezer), and the atom can be transferred back and forth between two traps with high efficiency. The intensity noise spectra of tweezer laser are measured and the heating mechanisms in optical tweezer are analyzed. To prolong the lifetime of single atom trapped in optical tweezer, laser cooling technique is utilized to decrease atom's kinetic energy, and the effective temperature of single atom in tweezer is estimated by the release-and-recapture (R&R) method. Thanks to laser cooling, typical lifetime of ~ 130.6 ± 1.8 s for single atom in tweezer is obtained. These works provides a good starting point for coherent manipulation of single atom.

Antoine Browaeys, Charles Evellin, Tatjana Wilk +12 more