Physical Review Letters
Two-dimesional atomic crystal bound by light
Andreas Hemmerich, Theodor W. Hänsch
Abstract
We have observed the vibrational levels of rubidium atoms spatially confined in two dimensions by two crossed optical standing waves (oriented along the x and y axes) with mutually orthogonal linear polarization (in the x-y plane). When the two standing waves oscillate with a 90\ifmmode^\circ\else\textdegree\fi{} time phase delay, the atoms are confined by dipole forces to the intensity maxima forming a two-dimensional collimated array of linear de Broglie waveguides, spaced by half an optical wavelength. When the standing waves oscillate in phase no vibrational energy structure can be observed.