Atom Localization in two and three dimensions via level populations in   an M-type atomic system
  Schemes for two-dimensional (2D) and three-dimensional (3D) atomic states localization in a five level M-type system using standing-wave laser fields are presented. In the upper two levels of the system we see a `coupled' localization for both 2D and 3D case. Here, the state in which majority of population will be found depends on the sign of the detunings between the upper levels and the intermediate level. The experimental implementation of the scheme using the D2 line of Rb is also proposed. The scheme may be manipulated to achieve subwavelength localization of atoms in one dimension to a spatial width, smaller by a factor of 1000 than the incident wavelength. 
Nilesh Chaudhari and Amarendra K. Sarma
physics.atom-ph physics.optics quant-ph