What tool arranges the atoms?

Optical tweezers are the tool: tightly focused laser beams create a point of intense light that can grab a single neutral atom and hold it in place, the way a pair of tweezers grips a small object. Because the atoms carry no net charge, they cannot be trapped with the electric fields used for ions, so researchers instead rely on the physical push of focused light itself, arranging many of these light traps into a grid to build an array of qubits that can be reconfigured almost at will.

Magnetic rails are not the mechanism here, since neutral atoms lack the charge magnetic fields would grip, and sound waves play no role in positioning individual atoms in these systems.

Optical tweezers themselves earned a Nobel Prize in physics in 2018, recognizing decades of laser-based atom manipulation research turning into a practical engineering tool.