Research On The Anti-bunching Effect Of Photon And Magnon Based On Different Kerr Nonlinearity

It has been nearly 60 years since quantum optics was born and developed,and scientists have never stopped exploring the microscopic quantum world.Quantum information processing and its application have attracted widespread attention.Among them,in order to apply photons in quantum information,we need a single photon source,which makes it one of the popular quantum effects.Single photon source has become a typical and interesting quantum effect in quantum information application,and it has potential applications in quantum metrology research,such as quantum computation,quantum simulation,quantum communication and network.The preparation of ideal single photon source can be obtained by the physical mechanism of photon blockade.Photon blockade,that is,the first photon in an optical system blocks the excitation of the second photon,so that the photons are output orderly one by one,which is correspondingly called photon anti-bunching effect.We can observe many peculiar quantum effects in cavity optomechanical systems,and the photon blockade mechanism is one of them.Others include the ground state cooling and squeezed state preparation of mechanical oscillator,optomechanical entanglement and so on.As an important part of quantum effect,photon anti-bunching effect has been widely studied in different experimental schemes,such as quantum optomechanical system,nonlinear optical system,quantum dot cavity coupling system,second-order and third-order nonlinearity and so on.In this thesis,we mainly study the anti-bunching effect based on different Kerr nonlinear.Firstly,an optomechanical system consisting of two optical modes coupled in a resonant cavity is proposed,and the generation of photon anti-bunching effect is observed based on the interaction between the two optical mode and the cross Kerr nonlinearity.For convenience,the photon blockade effect is studied by taking the detuning of two optical modes as equal,and combining the two modes into symmetric mode and anti-symmetric mode.In this thesis,symmetric mode and anti-symmetric mode can realize photon blockade effect,and strong photon anti-bunching phenomenon is observed.By using Hamiltonian and master equation to simulate numerically,the statistical characteristics of photons are obtained by numerical solution analysis,and the second-order correlation function is observed to search for the conditions when anti-bunching effect appears.At the same time,the optimal conditions are obtained by analytical calculation.We find that the cross Kerr interaction has a linear relationship with the coupling strength and frequency detuning difference between the two modes,and the coupling strength and frequency detuning between the two modes satisfy a quasi-linear relationship.In addition,this thesis also analyzed the change of photon anti-bunching effect under the action of dualmode driving and the existence of phase difference of dual-mode driving.It shows that tunable single photon source can be produced by adjusting a series of parameters such as cross Kerr interaction or coupling strength between two modes.Our research results have a good reference value for the realization of tunable single photon source in experiments,and provide the possibility for the realization of potential applications in the field of photon quantum information processing and quantum communication.Secondly,the realization of magnon blockade in yttrium iron garnet(YIG)ferromagnetic insulator is studied theoretically.We propose a system consisting of a threedimensional microwave resonator and two YIG spheres.The deformation of YIG spheres is caused by magnetostriction force,and the oscillator mode is decoupled to produce Kerr-like effect and Kerr effect of magnon to realize magnon blockade effect.The resonator is coupled with the magnon Kittel mode in two YIG spheres at the same time,but not with the oscillator mode.At the same time,there is no direct interaction between the two YIG spheres.We propose two different methods to realize magnon blockade through cavity-magnetic coupling.The first method is to use the strong inharmonicity of the decorated state of the magnetic subsystem to realize the magnon blockade.In order to further enhance the anti-bunching effect,we propose another quantum destructive interference method to generate and enhance the existing magnon blockade effect.We consider adding an external driving field to generate destructive interference paths that interact directly,and suppress the excitation of two magnons by destructive interference between different transition paths.Compared with the strong inharmonicity method,the quantum interference method can obtain stronger magnon anti-bunching effect.In this thesis,the theoretical scheme of realizing a single magnon source is given,and the theoretical possibility of quantum manipulation at a single magnon level is provided.