6533b823fe1ef96bd127f1bb

RESEARCH PRODUCT

Control of photoassociation of atomic Bose-Einstein condensates by laser field configuration

Mariam Gevorgyan

subject

Photo-associationCondensats de Bose-Einstein moléculairesExact trackingMolecular Bose-Einstein condensatesBi-confluent Heun functionsSuivi exact[PHYS.PHYS] Physics [physics]/Physics [physics]Nonlinear adiabatic trackingSuivi adiabatique non-linéaireFonctions bi-confluentes de HeunMagneto-association

description

In this work we show that it is to perform an efficient adiabatic passage in a basic quadratic-nonlinear quantum two-state system describing weakly bound molecule formation in atomic Bose-Einstein condensates through photoassociation by laser fields. An efficient adiabatic transfer is also possible if the third-order nonlinearities describing the atom-atom, atom-molecule, and molecule-molecule elastic scattering are taken into account. The transfer is achieved by choosing a proper detuning derived by solving the inverse problem.We also show that one can perform a stimulated Raman exact tracking in a quadratic-nonlinear quantum three-state system.The irreversible losses from the intermediate weakly bound molecular state in a passage of free atoms to the stable molecular state can be avoided by a two-colour three-state scheme in the case of one- and two-photon resonances for the associating laser fields.This is achieved by an exact tracking technique.We also studied the linear time-dependent two-state bi-confluent Heun models with solutions in terms of linear combinations of a finite numberof the Hermite functions of non-integer order.We have presented a model the solution for which involves just two Hermite functions.This is a resonance-crossing field configuration given by an exponentially diverging Rabi frequency and a detuning that starts from the exact resonance and exponentially diverges at the infinity. The model takes into account the irreversible losses from the second state.

https://theses.hal.science/tel-01701800