Control of the dynamics of coupled atomic-molecular Bose-Einstein condensates: Modified Gross-Pitaevskii approach

Effect of coupling strength on atomic-to-molecular condensate conversion in Raman photoassociation

“…In recent experiments, the technique of Feshbach resonance plays an important role in creation of cold molecules [3,4]. Besides this magnetoassociation process, in a number of theoretical [8][9][10][11][12] and experimental [1] studies, molecular BEC has been realized through Raman photoassociation. In Raman photoassociation, two coupling lasers of different frequencies are used for stimulated free-bound and bound-bound transitions.…”

“…Recent experiments [5,6] also demonstrate highly efficient two-photon transfer of Feshbach molecules into a deeply bound vibrational level. Coherent conversion of an atomic BEC to a molecular BEC via twophoton Raman photoassociation is important to study the quantum superchemistry of the system [9][10][11][12]. However, the molecules with a limited conversion efficiency can be created in the desirable stable ground state of molecular condensate via Raman photoassociation [9][10][11].…”

“…Coherent conversion of an atomic BEC to a molecular BEC via twophoton Raman photoassociation is important to study the quantum superchemistry of the system [9][10][11][12]. However, the molecules with a limited conversion efficiency can be created in the desirable stable ground state of molecular condensate via Raman photoassociation [9][10][11]. Therefore achieving high values of atom-to-molecule conversion efficiency in this twophoton Raman transition scheme is a challenging aspect.…”

“…By exploring coherent population trapping state in the Feshbach resonance-assisted stimulated Raman adiabatic passage technique, high efficiency for atom-to-molecule BEC conversions can also be achieved [16,17]. * mou mita 81@yahoo.co.in † krishna raidastidar@yahoo.co.in In our previous work [11], the dynamics of the coupled atomic and molecular system has been analyzed in a modified Gross-Pitaevskii approach considering higher order nonlinearity (Lee-Huang-Yang term) in atom-atom interaction for large values of scattering length. The effect of the effective twophoton Raman detuning on the dynamics of the coupled system has also been demonstrated, keeping other system parameters, such as laser intensity, atom-molecular coupling strength, spontaneous and stimulated decay rates, and scattering length, unchanged.…”

“…This is because of the fact that the effective s-wave atom-atom scattering length increases with the increase in the laser intensity, leading to an increase in the higher order nonlinear (Lee-Huang-Yang term) coupling. The effect of the Lee-Huang-Yang term becomes significant when the peak gas parameter is in the range of x pk 10 −3 (x pk = n pk a 3 , where n pk is the peak density of the system and a is s-wave scattering length) [11,18]. We show that the variation of laser intensity and the effective two-photon Raman detuning provides a tool to enhance the efficiency of molecular formation and also to change the frequency of oscillations between the atomic and molecular condensates.…”