Proposal of a free-space-to-chip pipeline for transporting single atoms

A free-space-to-chip pipeline is proposed for the efficient transportation of single atoms from a magneto optical trap to an on-chip evanescent-field trap. Due to the reflection of the dipole laser on the chip surface, the conventional conveyor-belt approach can transport only atoms in close proximity to the chip surface, with a distance of about one wavelength. This limitation hinders the efficient interaction between the atom and the on-chip waveguide devices. Here, a two-layer photonic chip architecture is proposed to realize a free-space to-chip atom pipeline. By employing a diffraction beam of the integrated grating with an incident angle of the Brewster angle, the reflection of the dipole laser is suppressed, allowing the atoms to be brought to the chip surface with a distance of only 100 nm. The pipeline is verified numerically and provides a reliable atom source for a hybrid photonic-atom chip.