Development And Application Of A Quantum Gas Microscope

In this thesis,the development and application of a high-resolution quantum gas microscope in the experimental field of ultracold atoms in optical lattices are studied.The technique enables high precision detection and manipulation of a quantum gas in an optical lattice with single-atom sensitivity.And it is powerful in quantum simulation and quantum computation experiments based on the optical lattice system.Firstly,we built an ultracold atom experimental system using 87Rb.Vacuum system,laser system,magnetic system,complex procedure controlling system,imaging system were all assembled together.We used MOT to collect and cool 87Rb atoms,and loaded them to a dipole trap to take evaporative cooling process drived by radiofrequency field.In the next the atoms were sent to a science chamber by laser and after the evaporative cooling in optical potential they went into Bose-Einstein condensed state.Then,we got pancake structure via loading the atoms into an one-dimensional optical lattice and obtained one single layer with the aid of magnetic technique and microwave technique.Finally we rose two-dimensional optical lattices in the layer.The experimental platform is the basis of following experiments.To develop a quantum gas microscope with single-site resolution is one of the most important parts in this thesis.According to the requirements of our system,we bought a custom-made high-resolution objective and a tubelens from Leica Microsystems,and accomplished the study about the various parameters of a high qualified vacuum viewport as the most crucial part of the imaging system.The IRR part of the viewport’s flatness mounted to the science chamber in reality is about 0.082 λ633nm(Dia.20 mm).Besides we developed a method by ourselves to manufacture high-resolution target containing pinholes with 100 nm radius for star testing.Furthermore the adjusting system from high-resolution system was designed and assembled.At last we got the highresolution at world leading level(690 nm resolution at 780 nm),and this allowed for a single-site-resolved reconstruction of the atomic distribution.We also observed the wedding-cake structure in a Mott insulator phase.Projecting particular two-dimensional optical potentials with spatial light modulators(LCOS-SLM and DMD)is also studied here.This part includes the statements of various implementation methods and simulations of related algorithms,ways to calibrate the devices and compensate aberrations,as well as a test of a LCOS-SLM.The application possibilities and practical schemes are discussed.With the assistance of the quantum gas microscope,we have been able to modulate the laser field and then construct specific potentials with details at a diffraction-limited level.Besides,we developed a new algorithm and obtained effective results in simulation.The successful development of a high-resolution quantum gas microscope and the reasonable application of the spatial light modulators have greatly improved our platform’s ability to observe and manipulate the ultracold atoms in optical lattices,and lay a solid foundation for the realization of more complex physical experiments in the future.