Faculty and Research Themes, Field of Physics and Applied Physics

We aim to acquire the fundamentals of scientific thinking and inquiry methods while learning the basics of fluid physics such as how to treat fluids represented by water and air as continua, methods of describing motion, and analytical methods. In particular, we deal with the ordered structure of turbulent flow on wall surfaces as a research theme, and discuss the bifurcation analysis of structures, vortex structures, turbulence maintenance mechanisms, and trends in applied technologies such as flow control to deepen understanding of phenomena.

Materials exhibit various properties such as magnetism and superconductivity. In this laboratory, we search for novel physical phenomena in nanoscale composite materials, particularly spintronics devices, and develop new functional devices. We aim to master quantum mechanics, statistical mechanics, and condensed matter physics necessary for understanding material properties, and to be able to use them as tools. We also learn about computer simulations for material analysis and property prediction, and challenge the development of new functional devices.

The atomic nucleus is a self-bound system where a finite number of microscopic particles such as protons and neutrons are bound together. Since protons and neutrons interact through the very complex strong force called the nuclear force, various aspects appear in the structure and reactions of atomic nuclei. Among them, we focus on "cluster phenomena" that view the atomic nucleus as a discrete collection of multiple sub-units (clusters), and elucidate structural changes and reaction phenomena involving cluster degrees of freedom. Recently, we are advancing research with emphasis on nuclear reaction and structure problems leading to nuclear waste disposal.

We aim to acquire the fundamentals of scientific thinking and inquiry methods while learning the basics of fluid physics such as how to treat fluids represented by water and air as continua, methods of describing motion, and analytical methods. As subjects, we deal with various flow phenomena in nature, especially blood flow in living bodies and various micro/nano-scale flow phenomena related to life phenomena, and discuss and deepen understanding of their mechanisms and relationships with biological functions.

With the miniaturization of electronic and magnetic devices, devices with unprecedented functions using new physical phenomena are expected to be realized. In this laboratory, we aim to develop new devices by elucidating physical phenomena, discovering them, and analyzing the electrical conduction and magnetic properties of devices. We cultivate the ability to analyze material properties from a theoretical perspective while learning condensed matter physics, electromagnetism, quantum mechanics, etc., and also learn numerical simulation methods and optimization techniques necessary for numerical analysis of device characteristics using computers.

Nucleons (protons and neutrons) that constitute atoms, which are the basis of matter, and electrons follow quantum mechanics and have the common property that only one particle can enter the same state. We elucidate the properties and reaction mechanisms of atomic nuclei and atomic clusters, which are collections of such particles (quantum many-body systems), from the basic properties of constituent particles and inter-particle interactions. We learn deeply about quantum mechanics and quantum field theory, and master physical thinking and problem-solving methods while making full use of computer simulations.

Matter is composed of the smallest "things" called elementary particles. Various elementary particles such as quarks, leptons, gauge particles, and Higgs have been discovered so far. However, there is also the possibility that undiscovered elementary particles exist; for example, based on the idea of quantum gravity theory that combines particle theory and gravity theory, a particle called graviton is predicted. In this laboratory, we explore the theoretical structure of undiscovered elementary particles and methods for experimental verification through future particle experiments and precision cosmic observations, and challenge to obtain new insights to elucidate the origin of matter and the universe.

When electrons move, photons are generated. Also, photons are absorbed by electrons and change their motion. This laboratory investigates such interactions between electrons and photons from three aspects: experiment, theory, and simulation. We apply the results to advanced scientific instruments such as electron accelerators, plasma generators, and free electron lasers. In seminars, we strive to improve basic mathematical skills and writing abilities.

Nano-sized materials exhibit properties different from bulk crystals due to quantum mechanical effects. In addition, in systems where adjacent nanostructures have interactions (nanostructure assemblies), new electronic systems can be expected to emerge due to the competition between quantum effects and many-body effects. In this laboratory, we thoroughly investigate the optical properties and electron transport characteristics of semiconductor, metal, and molecular nanostructures (assemblies) to clarify their generation mechanisms, and aim to develop environmental/medical sensors and information devices based on new operating principles that utilize them.

With the development of high-speed digital communication technology, research aimed at widely utilizing advanced technologies from microwave to terahertz wave bands in basic science and industrial fields is attracting attention. This frequency band is in the intermediate region between radio waves and light, and its technology is positioned in the gap between radio engineering and infrared optics, so it is attracting attention as a new development area for research. Development of laser light sources, establishment of measurement technology, and applications to biomedical imaging, space radio observation, non-destructive diagnostics, etc. are being advanced. Light waves interfere with each other through multiple propagation paths, and show electromagnetic wave radiation and dispersion characteristics through interactions with charged particles and dielectric media. Based on the fundamentals of electromagnetic fields, relativity, and dielectric properties, we aim to contribute academically to the field of imaging science through basic research such as terahertz light source development and wave computational tomography.

We learn the acoustic properties of biological tissues such as cartilage and skin, and soft materials such as gels and rubber. We aim to elucidate acoustic chemical effects (sonochemistry) such as polymer decomposition by ultrasonic cavitation and light emission (sonoluminescence) from a physical perspective. We also conduct basic research on new medical diagnostic methods and non-destructive testing methods using ultrasound, and develop devices that optically visualize ultrasound. We conduct research from the standpoint of exploring the properties of things using sound waves (acoustic properties of materials) and applying that knowledge and technology to medical and chemical fields (ultrasonic engineering).

Materials such as nanosheets and nanowires have unique quantum properties derived from low dimensionality and excellent external field responsiveness due to their huge specific surface area, so they are expected to be next-generation device materials that can replace existing semiconductor materials. In this laboratory, we experimentally clarify novel electron transport characteristics, light absorption/emission characteristics, and mechanical properties that appear in nanomaterials. We also develop new principle and high-performance devices that utilize the physical properties of nanomaterials.