Optical tweezers throw and catch single atoms

We present an experiment of single-atom throw-and-catch by optical tweezers. Optical tweezers are used to catch, accelerate and release (i.e., throw) single atoms, so that the atoms freely fly for a while, and then recapture and decelerate (i.e., catch) them. The successful throw-and-catch of single atom was recorded to be 94(3)% probability in experiments carried out with 35200(2700) m/s^2 acceleration. For the experiment, we used rubidium cold atoms [1]. The optical tweezers are first switched on to capture atoms in a magneto-optical trap, and then controlled to be accelerated, switched off and then back on, and finally decelerated, respectively, to throw, fly, and catch the atoms. The atoms are transported with a maximal speed of 0.5 m/s for a travel distance of 12.5 μm, and over a transportation efficiency of 90(3)%, even in the presences of other optical tweezers holding other atoms en route. This proof-of-principle experimental demonstration of flying atoms suggests possibilities of flying massive qubits, of which applications are promising in many quantum information technologies [2], such as quantum shuffle memory, non-photon quantum communication, and flying-qubit-based [3] quantum computing as well as in fundamental studies such as single-particle collisions. As an application of the flying atoms, we plan to explore Ryberg state qubit particle collisions.