The Experimental Study On The Preparation Of Ultracold⁸⁵Rb¹³³Cs Molecules In The Lowest Ground State Via The B¹?₁ Electronic State

Due to the special properties,such as tunable,long-range,and anisotropic dipole-dipole interaction,ultracold polar molecules have attracted extensive attention from physicists and chemists in ultracold chemistry,quantum computation,quantum simulation,and precision measurement.At present,the main way to prepare polar molecules in the ground state is to perform stimulated Raman adiabatic passage(STIRAP)of Feshbach molecules formed by magnetoassociation or high vibronic state molecules formed by photoassociation(PA).These processes require a magnetic or light field manipulation of the initial atomic state,while short-range photoassociation can continuously generate and accumulate ground state molecules.If a suitable intermediate molecular state can be found,it is possible to use STIRAP to directly transfer the scattered atomic state to the deeply bound molecular state.In this paper,the ultracold RbCs molecules with the lowest vibration ground state were prepared via the B1?1 state based on the ultracold atoms short range photoassociation technology.The population of the RbCs molecules in the vibration ground state and the transition between the ground state X1?+(v=0,J=1)and the excited state B1?1(v=3,J=1)were measured using depletion spectroscopy technology,and the related molecular constants are obtained,relevant parameters are provided for studying the stimulated Raman adiabatic transfer between atoms and molecules,and the efficiency of the transfer process is simulated based on the experimental parameter theory.The main work of this paper is summarized as follows:Firstly,based on the samples of ultracold atoms,through Blrli short-range molecular state preparation X1?+(v=0)RbCs molecules;The time-of-flight mass spectrometry was used to obtain the photo-association spectra of seven vibrational states of the electronic state B1?1,where v=3,4 is the first newly observed vibrational quantum state.Based on these spectral date,the relevant molecular constants ?e??e?e?Te of the state was obtained.Secondly,based on work one,the population of RbCs molecules at the lowest vibrational states were measured by depletion spectroscopy.Using the low power depletion spectrum,the natural line widths of the transitions X1?+(v=0,J=1)and B1?1(v=3,J=1)are obtained.The absorption formula of the energy level system obtains the electric dipole moment of this transition.Finally,based on the molecular parameters measured in work two,the theoretical simulation of the transfer efficiency of the atom via the B1?1(v=3)vibrational dynamics to the X1?+(v=0)vibrational dynamic excited Raman adiabatic process is used for the next step.Coherent transfer provides the basis for efficient preparation of RbCs molecules with the lowest transition kinetics.