Manipulation Of Polar Molecules And Precision Measurement

Polar molecules are widely used in the precision measurement and the manipulation simulation.In this paper,we investigate theoretically the production of the molecular beam with different methods,and the fine and hyperfine energy levels of PbF molecules are calculated.Besides,the novel method of compact miniature electrostatic curved mirror is described for decelerating and trapping molecules,and this new method can improve the sensitivity of the electron electric dipole moment（e-EDM）precision measurement significantly.The main content is as follows:Firstly,we study the methods to generate polar diatomic molecular beam.SrF,CaF,YbF,ThO free radicals and HfF⁺ions are taken as examples.Three methods are discussed including high temperature preparation,supersonic and buffer gas cooling.By comparing their experimental parameters,such as the molecular velocity,rotational temperature and the flux of molecule beam,and so forth.We choose a suitable method to prepare the molecular beam for the precision measurement.It is beneficial to use the secondary buffer gas cooling cell,which can produce slower,cooler molecular beams,for the beam source in our cryogenic experiments.Secondly,we calculate the ground state Hamiltonian of PbF.First,we introduce four kinds of Hund’s case coupling schemes and the scheme coupling of PbF.Second,we introduce the concept of effective spin and calculate the matrix elements of the effective spin Hamiltonian for the case of the PbF molecule.Third,on the basis of the concept of effective spin,we also calculate the matrix elements of Hamiltonian with external fields.This has laid a solid theoretical foundation for the electron electric dipole moment precision measurement with PbF.Finally,for the further measurement with better sensitivity,we present a novel scheme of compact miniature electrostatic curved mirror.We propose a compact microstructured electrostatic curved mirror that is not only to direct the beam of the molecules but realize the transverse bunching of molecules as well,resulting in significant improvement of the number of molecules in the reflected beam.By utilizing theoretical calculation and Monte-Carlo simulation method,we examine the reflecting effect of the mirror of deuterated ammonia（ND₃）molecule and compare the results of the curved mirror with the planar mirror of the same size.In addition,the simulation results of the curved mirror of lead fluoride（PbF）molecule are discussed by the same method mentioned above and compared with those of deuterated ammonia（ND₃）.It indicates that the curved mirror has better bunching effect than the planar one,and the curved mirror simulation results of PbF is better than that of ND₃.Therefore,a single microstatic curved mirror can form a gravitational and optical molecular cavity and capture high-density cold molecular samples in association with the gravitational field,while two curved mirrors can form a molecular cavity（similar to Fabry-Perot atomic cavity）and are used for molecular laser output.Our proposed electrostatic curved mirror can also improve the molecular density and the e-EDM sensitivity...