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A: Fachverband Atomphysik
A 27: Ultra-Cold Atoms, Ions and BEC III (with Q)
A 27.5: Vortrag
Donnerstag, 5. März 2009, 15:30–15:45, VMP 6 HS-C
Scattering of ultra-cold atoms by nano-cylinders — •Andrés Naranjo, Javier Madroñero, and Harald Friedrich — Physik Department, TU München, Germany
Different scattering properties, like quantum reflection, are studied for the interaction between an ultra cold atom and a grounded perfectly conducting cylinder. For this, an expression for the interaction potential of a cylinder-dipole configuration is derived for the non retarded regime. This is an acceptable model which assumes that the atom interacts via its dipole polarizability. The calculation uses the traditional Green’s function method in cylindrical coordinates imposing Dirichlet boundary conditions [1]. For large separations the potential exhibits explicitly the contribution of each of the dipole components to the interaction. It is shown that the radial and axial components share the same dependence on the separation r and cylinder radius R, namely 1/(r3log(r/R)), while the component perpendicular to these two has the form 1/r5 with a proportionality constant depending on the cross section area of the cylinder. The validity of this asymptotic behavior is numerically verified against the exact potential for realistic situations, e.g. helium atoms interacting with nanowires [2].
[1] J.A. Hernandes and A.K.T. Assis, J. Electrostatics 63, 1115 (2005).
[2] A. Naranjo et al., in preparation.