Research On Quantum Mechanical Effect And Application In Optical Cavity Coupling

Quantum computation and quantum communication cannot carry out without the realization,manipulation,and control of qubits,where qubits broadly correspond to two-level quantum systems.Photon has some advantages of processing information in quantum computing:it propagates fast,does not interact with the environment and can be easily manipulated.To realize and manipulate qubits,one can resort to a double-well potential system.For example,realizations of a double-well-based qubit have been demonstrated using superconducting circuits(SQUID).Therefore,we present an optical double-well potential system and study its quantum effects,such as photonic tunneling.Based on the double-well potential system we provide a new realization method for the physical implementation of qubits.Then,we design a cavity-waveguide-cavity(CWC)structure,and study the quantum mechanical effects of photons inside the CWC structure.The main work of this paper is as follows:1)By means of the CWC model,an optical double-well potential system is constructed from two optical resonators connected by a cut-off waveguide.The electromagnetic field distribution inside CWC is studied and the quantum theoretical model is established.It is proved that the symmetry breaking and energy level splitting caused by the quantum tunneling effect of the photon passing through the cut-off waveguide,thus forming an effective two-level photonic system.In addition,we simulated and analyzed the internal resonance spectrum through the simulation software FDTD Solutions,and compared with our theoretical results,which proved the feasibility of our theoretical model.2)The optimization of CWC structure and the application research of optical double-well potential system are presented.Analyze the impacts of the adjustment of the CWC structure parameters on the photon spectrum distribution,including changing the length of the CWC structure,the size of the narrow side,and the way of filling different media in the CWC.By comparing the simulation and theoretical results of FDTD Solutions,we verify our theoretical results.It is concluded that reducing the length will increase the difference between the symmetric solution and the antisymmetric solution of the double-potential well system,that is,the potential barrier will increase;for the discontinuous structure,the incident wave isTE₁₀ mode,the size of the narrow side has no effect on our structure,which is convenient to manipulate photons inside the CWC structure.When filling different media,the theory and the simulation results are consistent,which verifies the feasibility of our theory.Further,by means of the coupling between the two-level photonic system and a?-type atom system(i.e.,the dynamics of two-mode Raman-type processes),one can present a new kind of physical implementation for optical qubits.In contrary to the traditional scheme,in our case the two field modes carry qubits while the atom acts as an ancilla state,and the two modes do not correspond to two different types of photons,but to two possible quantum states of the same photon.Finally,based on the physical realization of the CWC structure of optical qubits,a new quantum network node is designed.This scheme has no limitation on the amount of detuning,and the coupling between photons and atoms can be very strong.