@article{11681, author = {M. Brown and Tobias Thiele and Chris Kiehl and Ting-Wei Hsu and Cindy Regal}, title = {Gray-Molasses Optical-Tweezer Loading: Controlling Collisions for Scaling Atom-Array Assembly}, abstract = {To isolate individual neutral atoms in microtraps, experimenters have long harnessed molecular photoassociation to make atom distributions sub-Poissonian. While a variety of approaches have used a combination of attractive (red-detuned) and repulsive (blue-detuned) molecular states, to date all experiments have been predicated on red-detuned cooling. In our work, we present a shifted perspective\textemdashnamely, the efficient way to capture single atoms is to eliminate red-detuned light in the loading stage and use bluedetuned light that both cools the atoms and precisely controls trap loss through the amount of energy released during atom-atom collisions in the photoassociation process. Subsequent application of reddetuned light then assures the preparation of maximally one atom in the trap. Using Λ-enhanced graymolasses for loading, we study and model the molecular processes and find we can trap single atoms with 90\% probability even in a very shallow optical tweezer. Using 100 traps loaded with 80\% probability, we demonstrate one example of the power of enhanced loading by assembling a grid of 36 atoms using only a single move of rows and columns in 2D. Our insight is key in scaling the number of particles in a bottom-up quantum simulation and computation with atoms, or even molecules.}, year = {2019}, journal = {Physical Review X}, volume = {9}, pages = {011057}, month = {2019-03}, url = {https://journals.aps.org/prx/abstract/10.1103/PhysRevX.9.011057}, doi = {10.1103/PhysRevX.9.011057}, }