The fact that a single neutral atom stored in an optical micro-trap is very well isolated from the environment makes it attractive for application in a quantum logic device. Scaling such a device requires a consistent and efficient method of loading a single atom into the micro-trap. By inducing light-assisted collisions between trapped pairs of atoms we observe the outcome of individual collision events. This allowed us to devise a method that enables a loading efficiency of 83% of a single atom into a micro-trap. Furthermore, we are able to accurately count the small number of atoms using fluorescence imaging at high densities while minimizing loss through light assisted collisions.
The fact that a single neutral atom stored in an optical micro-trap is very well isolated from the environment makes it attractive for application in a quantum logic device. Scaling such a device requires a consistent and efficient method of loading a single atom into the micro-trap. By inducing light-assisted collisions between trapped pairs of atoms we observe the outcome of individual collision events. This allowed us to devise a method that enables a loading efficiency of 83% of a single atom into a micro-trap. Furthermore, we are able to accurately count the small number of atoms using fluorescence imaging at high densities while minimizing loss through light assisted collisions.
Scalable arrays of individual atoms provide an ideal starting point for quantum information and simulation experiments. However, their preparation is often limited by light-assisted collisions (LACs), which typically result in parity-projected filling fractions of
f≈0.5. In this work we demonstrate a light-assisted redistribution process in the Quantum Matter Synthesizer that overcomes this constraint by stochastically moving atoms from multiply occupied lattice sites to neighboring vacant sites. Using a blue-detuned optical pumping beam during degenerate Raman sideband cooling, we achieve single-atom filling fractions of
70−80%. We find that over 50
% of the atoms involved in radiative collisions are retained in the lattice. The redistribution process involves many LACs over an extended time as atoms diffuse to empty sites. Our demonstration offers a scalable and efficient pathway toward unity-filled atom arrays without the need for complex rearrangement protocols, with broad applicability to quantum simulation, precision measurements, and quantum information control.
We review light assisted collisions in a high-density far-off resonant optical trap (FORT). By tuning the parameters of the light that induces the collisions, the effects of the collisions can be controlled. Trap loss can be suppressed even at high atomic densities, allowing us to count the atoms using fluorescence detection. When only two atoms are trapped, individual loss events reveal new information about the process, and the simplicity of the system allows for a numerical simulation of the dynamics. By optimizing the experimental parameters, we implement an efficient method to prepare single atoms in the FORT. Our methods can be extended to load quantum registers for quantum information processing.