Theory of one-dimensional trapping of atoms by counterpropagating short pulse trains

We have developed a theory of the one-dimensional atomic trap formed by the resonant counterpropagating trains of the short small-area laser pulses. Atoms are trapped in the region where the counterpropagating pulses 'collide'. We have derived the effective Hamiltonian which allows us to consider an atom in the polychromatic field of the pulse trains as the atom with the spatially modulated transition frequency in a standing monochromatic wave. We have obtained the expressions for the coordinate-dependent force exerted on the atom and the atom potential energy. The value of the potential barrier for typical femtosecond laser parameters for an atom with mass ∼100 amu is approximately 15 mK.