Research On Optical And Magnetic Properties Of Confined Nanostructures

With the rapid development of 5G communication technology,medical electronics,flexible wearable devices,functional electromagnetic devices and high-speed information technology processing,electronic devices begin to develop towards miniaturization.However,when the size of the structure is reduced to nanometer,the material shows some special properties due to the emergence of quantum effect and size effect.Therefore,it is important to explore the properties of materials at the nanoscale.The preparation and operation of electronic devices in nanoscale have become one of the hot spots in the current research.Correspondingly,it is in demand to study and manipulate the optical properties and magnetic properties of functional electromagnetic devices by using the confined nanostructures.In this work,we designed different confined condition by controlling the dimension and the shape of the nanostructures.The properties of our sample are studied by combining of theoretical calculations and experimental measurements,where the physical mechanism is also analyzed systematically.(1)Research on Optical Properties of Confined Nanostructures:Nanogap plasmonic structures with strong coupling between separated components have different responses to the orthogonal polarized light,giving rise to giant optical chirality.Here,we proposed the 3D nanostructure consisting of two vertically and twistedly aligned nanogaps,showing a hybridized charge distribution within 3D structures.It is discovered that the structure twisted with 60~o performs plasmonic coupling behaviour with/without gap mode for different circular-polarized plane waves,showing a giant chiral response(?T)of 60%at the wavelength of 1550 nm.By controlling the disk radius and the insulator layer,the CD signal can be further tuned between 1538?1626 nm.(2)Research on Magnetic Properties of Confined Nanostructures:The confined nanostructures of 1D/2D are prepared by electron beam lithography.And the samples are studied by the micromagnetism simulation and the characterization of stress distribution.The magnetoelastic coupling between layers can be controlled by changing the distribution of stress within different confined structures.The distribution of internal stress can be adjusted by changing the size of nanoscale trenches,which affects distribution of magnetic domain in confined nanostructures.Thus,this method provides an accurate and feasible design specification for the controlling of magnetoelastic dynamics.Our results are also important for the development of magnetic microdevices.