In neutral atom quantum computers, the atoms are held in place with focused laser beams under shallow trapping potentials. Moreover, these traps are turned off when entangling operations are done, so the atoms might escape or get kicked out of the trap and we would be none the wiser.
In this paper, our colleagues at Sandia national lab used circuit methods proposed all the way back in the early days of Quantum error correction to detect if an atom is present or if it has “leaked” out, without destroying the information in it.
Vikas Buchemmavari 