Outline of Nishii Laboratory
We are researching inorganic optical material with its robust frame structure, and are conducting research on the expression of optical functions through formation of nanostructures on the surface.
Moreover, we are undertaking basic research with an aim to extract novel functions and features of inorganic and metallic materials in the form of bulk bodies by controlling the states of ions and electron spin in the materials.
(1) Expression of light-wave control functions
A fine periodic structure below a light wavelength level expresses optical properties not existing in nature such as strong optical anisotropy and wavelength dependence, electromagnetic enhancement by resonance, and confinement of light waves.
By applying a variety of cutting-edge processes including vacuum film deposition, lithography, etching and electrical nanoimprint with voltage application, the laboratory is aiming for expression of such photonic functions as guided wave control, diffraction control, polarization control, reflection prevention, plasmon enhancement, and more.
(2) Ion control
The laboratory is engaged in basic research on significantly changing optical and electrical characteristics of a solid material by applying voltage to the material to replace the internal ions with other ions and to control the distribution of ionic concentration.
In particular, we have been focusing on alkali-proton replacement in a glass material employing non-contact electrodes or metal catalyst electrodes.
(3) Electron spin control
It is promising that introduction of "spin", a new degree of freedom for "electric charge" possessed by electrons in solids, allows us to create devices and materials with functions and capabilities which have never been realized in conventional electronics.
This research field is known as "spintronics". This laboratory is attempting to pioneer a new academic research field integrating spintronics with nanostructure and photonics.
New functions and features are understood by these studies are expected to be applied to diverse fields such as advanced information processing devices, sensors for environmental conservation or health management, and energy-saving devices.
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1. Expression of optical functions
* Development of optical devices employing nanoimprint lithography
* Development of plasmon optical elements
* Low-temperature imprint through voltage application
2. Ion control
* Control of glass-surface characteristics through corona discharge treatment
* Alkali-proton replacement using palladium catalyst electrode
3. Electron spin control
* Magnetoimpedance characteristics in ferromagnetic tunnel junction
* Fabrication of ferromagnetic nano-scale junction and its structure, electrical conduction and magnetism properties
* Surface and internal structures and magnetism properties of pulse-laser-irradiated magnetic alloy