Enhanced atom-by-atom assembly of arbitrary tweezer arrays

We report on improvements extending the capabilities of the atom-by-atom assembler described by Barredo et al. [Science 354, 1021 (2016)] that we use to create fully-loaded target arrays of more than 100 single atoms in optical tweezers, starting from randomly loaded, half-filled initial arrays. We describe four variants of the sorting algorithm that decrease the number of moves needed for assembly and enable the assembly of arbitrary, nonregular target arrays. We demonstrate experimentally the performance of this enhanced assembler for a variety of target arrays.