Research Of Unidirectional Reflectionless And Quantum Entanglement In Surface Plasmonic Cavity-waveguide System

With the rapid development of information technology,people are increasingly demanding miniaturized and highly integrated devices.The realization of optical information transmission and processing at the nanometer level has become an im-portant topic in scientific research.The advent of surface plasmons opened a new door for researchers.As an ideal new carrier of quantum information,surface plas-mons not only break the diffraction limit but also has strong local field.Surface plasmons have pave the way for exploring the strong interaction between the waveg?uide and the various resonators.At the same time,it has also been widely used in high-sensitivity biological detection,sensing and new light sources.This thesis mainly carries out the following research work:1、A non-Hermitian quantum system consisting of surface plasmonic loss cavity-waveguide is constructed to research single-band unidirectional reflection-lessness and non-reciprocal quantum entanglement.Research indicate that when phase shift φ=0.9301π of two surface plasmonic cavities,reflections for forward and backward directions are～0.9 and～0 at frequency 1.937 × 102 THz.Reflections for forward and backward directions are～0 and～0.9 at frequency 1.921 x 102 THz when phase shift 1.0699π.By appropriately adjusting the phase shift of two surface plasmonic cavities,unidirectional reflectionlessness is obtained at exceptional points.And the bilateral unidirectional refiectionless propagations can be manipulated in a wide range of decay rate.Moreover,highly non-reciprocal entanglement states between two surface plasmonic cavities are obtaiied under appropriate the phase shift and decay rate,aiul maximum eiitauglement value can approach 1.2、A non-Hermitian quantum system composed of a surface plasmonic gain cavity and a loss cavity and a waveguide is constructed to realize dual-band uni-directional reflectionlessness and non-reciprocal quantum entanglement.Research indicate that reflections for forward(backward)direction are～0(～1.5)and～4.5(～0)at wavelengths λ=653.8 nm and 655.6 nm when phase shift θ=0.9π,respec-tively.When phase shift θ=1.1π,reflections for forward(backward)direction are～4.5(～0)and～0(～1.5)at wavelengths λ=664.4 nm and 666.2 nm,respectively.Unidirectional reflectionless propagation at different wavelengths can be investigated by adjusting the phase shift between two surface plasmonic cavities.And control-lable unidirectional reflectionlessness is achieved over a wide range of phase shift and decay rate.In addition,high non-reciprocal entanglement is obtained in the wide range of decay rate.And the highly entangled value appears at the position of unidirectional reflectionless peak.