Opto-thermophoretic superlattice for atoms

We propose and study a dissipative optical superlattice for manipulation of resonant particles (atoms, ions and similar ones) located in a transparent buffer gas. Its working principle is based on the simultaneous effect of a longitudinal rectified gradient force and a transverse thermophoretic force in the field of collinear superposition of bichromatic cosine-Gaussian laser beams. As a result, there occurs a strong periodic stratification of the gas manifested in the accumulation and sharp localization of the resonant particles at the nodes of the superlattice and their cooling. Moreover, in the case of linearly polarized light beams, there appear circulating currents of the resonant particles (the so-called Brownian vortices) in the gas. Unlike the traditional dissipative optical lattices, in the superlattice under consideration, transverse particle confinement is implemented only due to the light-induced thermophoretic force, associated with the finiteness of the effective radius of the light beams.