Atom symmetry breaking and level coupling in atom-surface van der Waals interaction

Summary form only given. Summary from only given. In the non retarded regime, atom-surface van der Waals (vW) interactions originate in the forces between the fluctuating atomic dipole and its instantaneous image linked to polarisation charges induced in the surface. vW interactions which are generally attractive (distance law in 1/z3) are of fundamental importance in many fields of physics. The existence of vW repulsion has recently been demonstrated when there is a resonant coupling between the fluctuating atom dipole and a surface resonance. We have started an experimental study of surface-induced wave function mixing between the 3P/sub 0/ and 3P/sub 1/ metastable states of argon. A thermal metastable argon beam is velocity selected thanks to a time of flight (TOF) technique.