Trapping A Single Atom And Manipulating The Coupling Strength In An Optical Micro-cavity

The single-atom cavity quantum electrodynamic system connected by photon provides a good platform for the study of scalable deterministic quantum information processing.The realization and improvement of single-atom trapping technology in micro-optical cavity enable people to carry out research on quantum information processing and quantum simulation based on single atom-single photon.The technology for trapping and manipulating individual atoms or atomic arrays in free space is mature.However,in the micro-optical cavity,the space of light is greatly limited,which poses a challenge to cooling,trapping,and precisely manipulating the position of individual atoms in the microcavity.At present,several research groups have proposed atomic cooling mechanisms,such as Doppler cooling,polarization gradient cooling,vacuum-induced three-dimensional cooling,etc.Atomic transfer and trapping have been developed from the initial hot atom beam,atomic fountain,atomic free fall,etc.,to the method of atomic conveyor belt combined with three-dimensional optical lattice in the cavity,the external state of the atom is well controlled,and the trapping time of a single atom in the cavity ups to one minute.As the key to realizing single-atom strongly coupled cavity quantum electrodynamic system,it is still necessary to develop new methods for the trapping of single atoms in the cavity and realize the precise manipulation of the atomic position.This paper mainly contains the following contents:1.The construction of a single microscale optical dipole well in a microcavity was Studied.In the experiment,a laser beam with a wavelength of 1080 nm is focused by a high numerical aperture achromatic lens group(NA=0.4),and forms a single red detuned optical dipole trap with a waist of 2 μm for the trapping of a single cesium atom in the micro-optical cavity.2.The trapping of single atoms in optical cavity was Studied.In the experiment,the cesium atom assemble is transferred from MOT to the cavity mode by an optical dipole trap,and then the two-dimensional PGC cooling mechanism is used within the optical tweezer to trap a single Cs atom.Finally,single atom is trapped in the cavity with a lifetime of 2.6 ± 0.18 s.3.The manipulation of atom-cavity coupling strength in optical cavity was Studied.In the experiment,the optical tweezer is settled on a high-precision translation stage,and the position of the optical tweezer is controlled on the sub-micron scale,and thus,the position of the single atom can be moved in the three-dimensional direction,so as to realize the precise manipulation of the atom-cavity coupling strength.