Atomic (or molecular) guiding using a blue-detuned doughnut mode in a hollow metallic waveguide

We propose a new scheme to guide cold atoms (or molecules) using a blue-detuned TE(01) doughnut mode in a hollow metallic waveguide (HMW), and analyze the electromagnetic field distributions of various modes in the HMW. We calculate the optical potentials of the TE(01) doughnut mode for three-level atoms using dressed-atom approach, and find that the optical potential of the TE(01) mode is high enough to guide cold atoms released from a standard magneto-optical trap. Our study shows that when the input laser power is 0.5W and its detuning is 3GHz, the guiding efficiency of cold atoms in the straight HMW with a hollow radius of 15 microm can reach 98%, and this guiding efficiency will be almost unchanged with the change of curvature radius R of the bent HMW as R > 2cm, which is a desirable scheme to do some atom-optics experiments or realize a computer-controlled atom lithography with an arbitrary pattern. We also analyze the losses of the guided atoms in the HMW due to the spontaneous emission and background thermal collisions and briefly discuss some potential applications of our guiding scheme in atom and molecule optics.