Use of Bessel J(1) laser beam to focus an atomic beam into a nano-scale dot

We propose a novel scheme to guide atomic beams with submicrometer spot siz es and beam propagation lengths of more than 1 centimeter. By using a Besse l J(1) beam for guiding atoms, the atoms are confined to the center dark re gion of the doughnut mode of J(1) beam. Our numerical analysis results show that a guided atomic beam maintains its width which is less than 100 nm. W e also propose a scheme which combines the Bessel J(1) beam with a magneto- optical trap and a Besset J(0) beam, where the unfocused part of an atomic flux. i.e.. the background component, is suppressed.