Physical Review A
Resonance collisions between three-level systems in an intense laser field
Stephen Michael Radley Young, D. M. Segal, H. Shah, Keith R. Burnett
Abstract
Theory relevant to the treatment of resonance collisions between two-level dressed atoms has been extended to the three-level case in a self-contained calculation of field-dependent collision rates. With the laser field tuned close to the \ensuremath{\Vert}${\mathit{e}}_{1}$〉\ensuremath{\leftrightarrows}\ensuremath{\Vert}${\mathit{e}}_{2}$〉 transition, dressing of the upper two-level system is achieved. We solve coupled equations of motion for two-atom states that describe one atom in the ground state and the other in one of two dressed states. Dressed-state collision rates are calculated within the impact approximation using S-matrix theory. The coupled equations of motion are simplified in the limit of intense field. We have applied the theory to describe approximately collisions between Ne atoms in fields intense enough to dress the collision complex.