Research On The Scalar Aharonov-Bohm Effect Based On Cold Atom Interferometry

The Aharonov-Bohm effect(AB effect)is an important interference effect in quantum mechanics,which indicates that nonzero potentials could still affect the phase of wave function of a microscopic particle even though there are no forces in the moving path of the particle,and this influence could be shown by means of matter wave interferometry.In recent years,the AB effect induced by scalar potential has been investigated widely.However,the essence of topological characteristics of this effect is still unclear up to now.This thesis is going to study the scalar AB effect and its topological characteristics by using cold atom interferometer consisted of two Raman pulses,and the scalar potential is produced by the quadratic Zeeman effect of the atom.The fine structure and hyperfine structure of alkali metal atoms and the Zeman effect under the action of external field are introduced in great details.The theory of stimulated Raman transition is analyzed,and the transition probability of the atoms has been obtained for two-pulses Ramsey-bordé interferometer.The we introduce the Dopplerinsensitive atom interferometer briefly.In this experiment,the atomic interferences are realized by the preparation of cold atoms,state selection of cold atom,Raman pulse sequence interaction with atoms,atomic fluorescence detection and so on.The atomic interference fringes were obtained.A pulse of bias magnetic is then applied between the two Raman pulses,which yields a region with potential but no force.By fitting the interference fringes obtained from the two experiments and comparing the phase information extracted,it is found that the fringe has been moved,which verifies the AB effect in the experiment.In this paper,the topological properties of the scalar Aharonov-Bohm effect are studied,and the main contents include: 1)The geometric topological property of the scalar AB effect has be investigated by exploration of the dependence of the phase of interference fringe on the moving paths and the enclosed area of the interference paths;2)The nondispersive feature of scalar AB effect has be studied by analyzing the changes of the contrast of atomic interference fringe with the scalar potentials;3)The experimental verification of the scalar AB effect has be carried on by measuring the quantitative relationship between the phase shifts of the interference fringes and the amplitude of the scalar potential.The investigation of topological features of scalar AB effect in this subject is beneficial for the further comprehension of the basic theory of quantum mechanics,and valuable for the potential applications in the improvement of performance of quantum sensors such as atomic clock,atomic gravimeter,etc.