Summary form only given. Our recent experimental work on the specular reflection of very slow atoms from a solid surface which is caused by attractive van der Waals potential near the surface and its applications will be discussed.
The coherent reflection of ultra-cold neon and helium atoms from silicon surfaces and surface structures is measured and analyzed. When the silicon surface is flat, the reflection is explained by the quantum reflection due to van der Waals attractive potential near the silicon surface. When the silicon surface is modified to form a grating structure, the reflectivity increases dramatically. For certain ranges of surface structure parameters, the reflection may be interpreted as a coherent summation of Fresnel diffraction of the atomic wave at the ridges of the grating structure.
We study the photoassociative process between cold atoms and a surface. A mechanism to confine free cold atoms in a planar waveguide, characterized by the long-range atom-surface van der Waals potential and based on radiative transitions, is presented. We propose that the vibrational states of this potential can be probed by reflection spectroscopy, giving information about the C3 van der Waals coefficients.