Measurement Of Transition Dipole Moments Of Ultracold ⁸⁵Rb¹³³Cs Molecules

Ultracold polar molecules have long range dipole-dipole interactions with anisotropy,which play an important role in quantum simulation,quantum computation,ultracold chemistry,precision measurement,and multibody physics of strong interactions.The preparation of ground state ultracold polar molecules is the basis and key to realize the above research.The transition dipole moment represents the transition strength between the initial state and the final state of an atom and molecule,and the yield of the molecule can be increased by selecting the molecular energy level with the maximum coupling strength in the process of molecule preparation.Therefore,it is very important to measure the transition dipole moment of an ultracold polar molecule.This article,based on the short-range photoassociation technology of ultracold atomic,implements the the preparation of ultracold RbCs molecular rovibration state of X1?+(v=0,J=1).And using depletion spectroscopy to measure the transition dipole moments between ground state X1?+(v=0,J=1)of RbCs molecules and the excited state of 23?0+(v=10,J=2),21?1(v=22,J=2)state.The method used in this paper can be used to find more molecular states strongly coupled with the ground state,laying a foundation for the direct stimulated Raman adiabatic transfer from the scattered atomic state to the bound molecular state,and also can be applied to other kinds of atomic and molecular systems.The main work of this paper is summarized as follows:Firstly,based on the samples of ultracold atoms,through 23?0-(v=11,J=1)short-range molecular state preparation X1?+(v=0)minimum vibration RbCs molecules;A pulse ionization laser beam of 651.8 nm was used to detect the vibration levels of inglet RbCs molecular.Secondly,an external cavity semiconductor laser is fabricated,and the tunable range of the laser is increased by using a current-voltage coupling feedback circuit.By depletion spectroscopy technology,we achieved the detection of the ground state X1?+(v=0,J=1)rotation resolution for RbCs molecular.Finally,we got the natural line width of molecular state 23?0+(v=10,J=2)and 21?1(v=22,J=2)by measuring the changes in the relationship between full width at half maximum of the depletion spectroscopy and the depletion laser power;and we obtained the transition dipole moment of excited states 23?0+(v=10,J=2),21?1(v=22,J=2)molecular and ground state molecules X1?+(v=0,J=1)by measuring the relationship between the depletion rate and depletion laser power,irradiate time,combined with the classical absorption formula of the two-level system.