Optical tweezers throw and catch single atoms

TL;DR

This paper demonstrates a novel method of transporting single cold atoms over short distances using optical tweezers without guiding them, enabling potential applications in quantum communication and computing.

Contribution

The study introduces and experimentally validates a technique for throwing and catching freely-flying atoms with optical tweezers, expanding capabilities for quantum information processing.

Findings

Achieved atom transport speeds up to 0.65 m/s

Transport efficiency of 94(3)% over 12.6 micrometers

Demonstrated atom arrangements and scattering with flying atoms

Abstract

Single atoms movable from one place to another would enable a flying quantum memory that can be used for quantum communication and quantum computing at the same time. Guided atoms, e.g., by optical tweezers, provide a partial solution, but the benefit of flying qubits could be lost if they still interact with the guiding means. Here we propose and experimentally demonstrate freely-flying atoms that are not guided but are instead thrown and caught by optical tweezers. In experiments, cold atoms at 40 micro Kelvin temperature are thrown up to a free-flying speed of 0.65 m/s over a travel distance of 12.6 micrometer at a transportation efficiency of 94(3)%, even in the presence of other optical tweezers or atoms en route. This performance is not fundamentally limited but by current settings of optical tweezers with limited potential depth and width. We provide a set of proof-of-principle flying atom demonstrations, which include atom transport through optical tweezers, atom arrangements by flying atoms, and atom scattering off optical tweezers. Our study suggests possible applications of flying atoms, not only in fundamental studies such as single-atom low-energy collisions, but also non-photon quantum communication and flying-qubit-based quantum computing.