Control of Nonadiabatic Processes by an External Field

S. Guérin

Yoshiaki Teranishi, Hiroki Nakamura

A new idea of controlling nonadiabatic transitions by an external field is proposed. The basic principle is to periodically sweep an external field at each level crossing to make the overall transition probability from an initial state to any desirable final state equal to unity. The recently completed semiclassical theory of nonadiabatic transition enables us to analytically deal with this problem. The present idea may be applicable to various physical and chemical problems, whenever level crossings are created by an external field.

A. Bulatov, Boris E. Vugmeister, Alexander L. Burin +1 more

We investigate coherent control of atomic translational motion in an applied off-resonance dipole optical potential. Since spontaneous emission can be neglected in this regime, the problem is treated as one of coherent momentum transfer. We consider both adiabatic and nonadiabatic regimes of cooling in the framework of the Wigner function formalism. For the adiabatic case, an approximate solution is obtained corresponding to the cooling envelope for an arbitrary time dependence of the external field. The nonadiabatic cooling process is formulated in terms of optimal control theory in order to define the most favorable regime of cooling under imposed constraints on the intensity of the control field. We find that the applied control field yields a significant reduction of the effective temperature of the atoms.

N. A. Chigir

Patrick F. O’Mahony