Investigation Of Ultracold Heteronuclear Collision In A Dual Species ²³Na-¹³³Cs Magneto-optical Trap

With the development of ultracold atomic technology,the study of ultracold atom collision has attracted great interest.The study of ultracold atom collisions has many important values: First,through the study of ultracold atom collisions,we can understand and quantify collisions effects in a magneto-optical trap?MOT?,so that the number of trapped atoms,temperature,atomic density and other parameters can be optimized to improve the quality of the atomic cloud;on the other hand,the collision of ultracold atoms can provide important information for the molecular potential energy curve acquisition,Feshbach resonance identification,Bose-Einstein condensation and other researches.The research of ultracold atom collisions has not only important position in atomic,molecular and photophysical fields,but also has important value and significance in the precision measurement of atomic and molecular parameters and using external fields to influence the outcome.The work of this paper is based on the collision properties between the ultracold sodium atoms and the ultracold cesium atoms in a dual-species magneto-optical trap.The collision loss rate of ultracold sodium atoms and the collision loss coefficient between ultracold sodium atoms and ultracold cesium atoms were measured as a function of Na trapping laser intensity.A Doppler model is used to calculate the Na atom trap depth,and the calculated critical intensity value agrees well with the experimental result.The main contents of this paper are as follows:1.Using the dual-species magneto-optical trapping technique,we simultaneously trap Na atoms and Cs atoms in the cell(10^-8 Pa),which paves the way for the study of collision properties between the ultracold sodium atoms and the ultracold cesium atoms.2.The loading curves of ultracold sodium atoms under different light intensities were obtained by changing the laser intensity of Na MOT.By fitting the loading curves,we obtained the Na trap loss rate and inter-species rate coefficients as a function of Na MOT laser intensity.3.A Doppler model is used to calculate the Na atom trap depth,and the calculated critical intensity value agrees well with the experimental result.