Theoretical Research Of The Manipulation Of Matter Waves By The Flat-topped Beam

Atom optics refers to techniques to manipulate the trajectories and exploit the wave properties of neutral atoms,and it plays an important role in the frontier fields of quantum information processing and high precision measurement.Lasers are important tools for manipulating ultra-cold atoms.In the past decade,laser shaping technology has developed rapidly,and various new beams,such as flat-topped beams,have emerged,further enriching the optical force control technology of atoms.Therefore,this paper has carried out the research on the manipulation of atomic matter-waves with the flat-topped beam.In this paper three problems are studied:1.We compare the refractive index of atomic matter-waves in blue detuned light field with that of light in plasma medium,and find that the mathematical form of them is very similar,and obtain the plasma-like optical mechanism in atom optics.2.We further apply the plasma-like optical mechanism to the research,and propose a theoretical scheme of using the super-Gaussian light as the rod atomic lens.The result shows that due to the difference of refractive index between the atomic matter-waves in the light field region and the non-light field region,the far-blue detuned flat-topped solid beam can split the incident wave,and the far-blue detuned flat-topped hollow beam can focus the incident wave.When the width of the incident atomic beam wave packet is less than or equal to the inner radius of the beam,the matter-wave can be focused to an area smaller than one wavelength of the light field under the appropriate incident kinetic energy.These results not only have potential applications in focusing and splitting of cold atoms,but also have some implications for the study of plasma rod lens.3.We propose theoretical simulations on the square potential barrier with the superGaussian beam.The result shows that a super-Gaussian beam with an order exceeding 20 could simulate a square potential barrier very well.Then we further studied the phenomenon of resonance tunneling in which the matter-waves incident into the double super-Gaussian barrier.The result shows that the position and number of the formant can be controlled by adjusting the distance between the barriers.This work provides a basis for the experimental verification of the tunneling phenomenon of the square barrier and the multi-barrier.