Research On The Quantum Optical Properties And Sensing In Two-Level Coupled Systems

Two-level systems can be combined with many quantum systems to form new hybrid system,which provide a good platform for investigating optical properties.The mechanical resonators made of carbon nanotubes,graphene and other nanomaterials have the advantages of high vibration frequency and high quality factor,which have great applications in quantum sensing,precision measurement and study of optical properties.The research based on two-level coupled systems has generated many interesting phenomena in the optical field,such as electromagnetically induced transparency,optical Kerr effect and vacuum Rabi splitting,which has very important application values in many fields,such as quantum computing,quantum storage,and the design of optical components.In this thesis,optical phenomena such as the optical Kerr effect,vacuum Rabi splitting,electromagnetically induced transparency and other parameters such as frequency and coupling strength measurements are studied based on a two-level coupled system.The following is the main content:Firstly,the optical properties and measurement of frequency of the hybrid system composed of diamond NV center coupled carbon nanotube and graphene resonator are investigated.The results show that electromagnetic induced transparency occurs under different coupling conditions.The equivalence between the position of the transparency window and the frequency detuning difference is illustrated,and the results show that the position of the transparency occurrence can be adjusted by changing the parameters.In addition,a method for measuring the coupling strength between diamond NV center and the current-carrying carbon nanotube and the vibration frequency of graphene resonator is proposed.Secondly,the Kerr effect in a hybrid system based on two-level emitter coupled with graphene resonator and cavity field is investigated.The Kerr coefficient at different pump field Rabi frequencies is discussed,and it is known that the stronger the Rabi frequency of the pump field,the larger the Kerr coefficient.The coupling strength of the two-level emitter coupled graphene resonator and the cavity field were compared on the Kerr coefficient,and it was found that the effects were different.The effects of the graphene mechanical resonator and the decay rate of the cavity field on the Kerr effect are investigated,which shows that the Kerr coefficient increases with the increase of the decay rate of the cavity field and decreases with the increase of the decay rate of the graphene resonator.Finally,a method for measuring the vibration frequency of graphene resonator is proposed.The results of this chapter can provide guidance for theoretical and experimental studies of hybrid quantum devices.Finally,a hybrid system consisting of atom,yttrium iron garnet(YIG)sphere and cavity field is proposed,and the Rabi splitting properties of the absorption spectra based on this system are investigated.The splitting characteristics of three different coupling conditions are also discussed for a certain coupling strength between the YIG sphere and the cavity field and between the atom and the cavity field.The results show that both YIG sphere and atom affect the characteristics of Rabi splitting.This work provides some help for the study of Rabi splitting in hybrid systems composed of atom,YIG sphere and cavity.