Study On The Integration Of Individually Addressable Single-Atom Arrays

As a highly-controllable quantum system,an array of single atoms can be widely used to investigate quantum coherent interaction,and it plays a great role in promoting the development of neutral quantum computing.This thesis carries out theorectical and experimental studies on the integration of individually addressable single-atom arrays.It includes scheme design for realizing chip-based single-atom arrays,experimental realization of atom chip U-MOT,high-resolution objective design,trapping and detection of single-atom arrays.The main noval results in the thesis are listed as follows:1.Noval design for single-atom array trapping.Existing schemes for the trapping of single-atom arrays are mainly depend on the laser interference and diffraction,which have limitations in individual addressing and stability of optical system.To address this problem,we proposed a noval experimental design that combines the advantage of optical waveguides and atom chips in miniaturization and integration.Then,we optimized and tested the main parameters of the components.And further more,we proposed two quantum control methods basing on Rydberg blockade mechanism and state-dependent microwave potential respectively.2.Realization of atom chip U-MOT.Quadrupole magnetic field can be generated by combining a current-carrying U-shape wire with a homogeneous bias field conveniently.With this field configuration,we have successfully achieved the ⁸⁷Rb U-MOT with an atom number of about 10⁷.The experimental setup mainly consists of ultral-high vacuum chamber,laser frequency stabilization and shifting,program controlling system and so on.Moreover,the atom number has been doubled by optimizing the axis of the MOT field.3.High-resolution objective design.Consisting completely of commercial singlets,we have designed a high-resolution objective for cold atom experiments.It has a numerical aperture of 0.44 and a long working distance of 35.9 mm.And also,this design can be well adopted to the excitation wavelength of all the alkalis and other vacuum window thickness by just modifying one lens spacing.we experimentally achieved single-atom trapping and detection by using this objective.4.Realization of single-atom array trapping and detection.We presented a new scheme for the trapping of single-atom arrays,which adopts multicore fiber to generate microtrap arrays.And it shows advantages in terms of individual addressing,beam pointing noise suppression and atom manipulation.According to the scheme,we have designed and fabricated an achromatic objective and a seven-core multicore fiber.The focal length difference of the objective at 780 nm and 830 nm is only 1.4 um,and the core-to-core distance of the fiber is about 40 um.After building up the vacuum and optical system,single-atom arrays with a spacing of about 11um have been trapped and detected in experiment.