The subjects of particle physics are the elementary particles – the most basic constituents of matter – and their interactions – the most fundamental law of Nature. Particle physics is also called high energy physics since the short-distance physics corresponds to the high-energy physics because of the uncertainty principle in quantum mechanics.
Nuclei are quantum mechanical many-body systems which consist of protons and neutrons. As they are self-bound systems with finite number of constituents, many rich and complex phenomena have been known to occur there. One of the primary goals of nuclear physics is to address them starting from the nucleon degrees of freedom.
The condensed matter theory group covers a large area of solid state physics and statistical physics, based on two fundamental frameworks; quantum mechanics and statistical mechanics.
Our group is a theoretical laboratory for quantum physics and materials science. By extracting the essence from the results of advanced numerical simulations, we aim to elaborate our understanding of quantum phenomena and create novel concepts in theoretical physics. Furthermore, by accumulating guidelines for predicting physical properties, we explore the frontier of materials science: theory-driven functional materials design.
The origin of elementary particle properties and the origin of matters in the universe are yet unknown in science. To resolve these mysteries, we are conducting researches using particle accelerators. Properties of a heavy quark and Higgs particle are studied in detail. Neutrinos are produced by accelerators and changes of their properties after traveling about 300 km are measured. We are also trying to catch special properties of neutrinos by developing a new type of detectors.
The Nature and the Universe provide us with a good laboratory for experiments on particle physics. A plenty of elementary particles are flying around us, some of which have the information of the birth and the evolution of the Universe, and others are continually emitted from the Galaxy, the Sun and the Earth and coming to the ground. The purpose of non-accelerator experiments is to detect these particles and study their characteristics and the Universe.
Thanks to recent progresses of accelerator techniques, the frontier of the nuclear science is rapidly expanding. Fig. shows some topics of the modern nuclear physics. Now it becomes possible to produce and experimentally study various exotic nuclei under extreme conditions. Our way of understanding materials is rapidly changing due to recent progresses of those studies.
The Nuclear Science Group conducts research in nuclear and hadron physics, accelerator and beam physics, and nuclear and radiochemistry based on the facilities at the Mikamine Office of the Research Center for Accelerator and Radioisotope Science (RARIS). RARIS-Mikamine is "Joint Usage and Research Center (Electron Photon Science)" approved by MEXT, and operates three electron linear accelerators and a 1.3 GeV electron synchrotron.
Nuclear Radiation Group conducts wide range of research, nuclear physics, accelerator science, radiation detector development, and medical application. Our group consists of Accelerator and Nuclear Physics Laboratory and Applied Nuclear Physics Laboratory. Research Center for Accelerator and Radioisotope Science (RARIS) is base of our group, and a cross-disciplinary facility and aims to promote the versatile use of accelerators and manage radioactive isotopes (RIs), including short-lived and high-level RIs.
Our group carries out research of nuclear and particle physics with high-intensity proton accelerator and other accelerators.
We study the electronic structure of strongly correlated electron materials such as high-temperature superconductors with ultrahigh-resolution angle-resolved photoemission spectroscopy (ARPES). ARPES is a unique and powerful experimental technique to directly observe the momentum-resolved electronic structure. We have constructed an ultrahigh-resolution ARPES spectrometer in our laboratory and the present energy resolution is in the world-best level.
We are currently studying nano size materials comprised of IVth-group elements of C, Si, Ge and Sn, for achieving new insights to fundamental understanding in solid state physics of nano materials, as well as development of advanced electronic devices in the next generation.
Low Temperature Quantum Physics Group performs the experimental researches in condensed matter physics at very low temperatures, in high magnetic fields and under high pressures. Besides the developments of new techniques and detection systems under such extreme conditions, synthesis of novel materials and growth of high quality single crystals are other major activities of the group.
When a macroscopic number of electrons are strongly correlated with each other, a novel quantum state characterized by the symmetry breaking and/or topological anomaly frequently emerges. Examples include superconductivity, spin liquid, and quantum Hall effect. Elementary excitations from such quantum state are completely different from one electron itself.
Highly correlated electron systems in 5f-, 4f- and 3d-compounds as well as low-dimensional organic compounds show various interesting physical properties such as metal-insulator transition, valence fluctuation, heavy-electron behavior, multipolar ordering and lowdimensional quantum spin behavior.
Our group investigates electrodynamics of water molecules, protons, electrons, ions, biological molecules confined in various types of nanospaces such as one-dimensional channels, two-dimensional narrow spaces and cage spaces. The electrodynamics is an interdisciplinary subject associated with biochemistry, medical and environmental science and energy problems, etc. Now we focus on the following subjects.
In strongly correlated electron systems, new phenomena can appear due to a complex combination of degree of freedom of the electron (charge, spin and orbital). To understand the mechanism, for instance, high Tc superconductivity, low dimensional quantum spin phenomena, electronic charge segregation and so on, it is quite important to obtain the information of not only basic structure but also the dynamics of materials with strong electron correlations.
We investigate a variety of physical phenomena of condensed matters in strong magnetic fields. Magnetic field is unique environment that strongly couples with the spin and the charge of electron. We are searching for new phenomena and new phases appearing in very strong magnetic field.
Our group studies low-temperature electrical properties of various superconductors and highly-correlated magnetic materials, such as transition metal oxides, iron-based pnictides, and Ce-based-compounds.
The main research subjects in this group are the experimental investigations of the organic molecular conductors. The characteristic properties of the organic materials are multiple flexibilities owing to the assemble structure of nanometer-size molecules.
Strongly Correlated Electron Physics Group consists of three guest professors belonging to national and independent research institutes.
The life is molecular assembly system composed of amphiphilic molecules, macromolecules, and so on, i.e. so-called soft matter. However, it has unique features, such as metabolism, proliferation, homeostasis, and morphogenesis, which never observed in the condensed matter. The aim of our laboratory is to reveal underlying physics of the life system based on non-equilibrium soft matter physics.
We study the quantum properties of light and matter and their interactions for finding new quantum optical and solid-state functionalities and applications. Our current research interests include quantum entanglement, quantum interference of light, nonlinear optics at a single-photon level, and quantum information and measurement applications. We also study novel optical materials such as conjugated pi-electron systems, metamaterials, and optical spintronics, using ultrafast and nonlinear spectroscopic techniques.
Our research group is aiming at the ultrafast optical/THz manipulations of corrective electron and spin motions in solids by using advance light source such as mono-few optical cycle IR pulss and THz pulse.
The semiconductor industry that supports modern life is based on a variety of advanced technologies, including ultra-high quality crystal growth and nano-device fabrication. Taking advantage of this technology, we create devices using ultra-high quality semiconductors and novel functional materials. These devices are the stage on which we conduct experiments to explore the novel physics of solid-states. We currently aim at implementing quantum cosmology in the laboratory in a toy model which is a theoretically equivalent physical system to the early universe or black holes. In this way we seek to provide a rich playground for verification of quantum cosmology.
In magnetic materials, novel physical properties are emergent when the crystal and/or spin structure are peculiar in terms of topology or symmetry. Such physical properties may give rise to useful material functions. This research group studies the emergent material functions induced by topology or symmetry breaking in magnetic materials.
Our research targets are understanding of fundamental crystal growth mechanisms and development of crystal growth technology for obtaining high-quality materials.
We investigate solid surfaces and interfaces at atomic level in order to create surfaces and interfaces with various functions. We have developed several original techniques for surface analysis, such as correlated thermal diffused scattering (CTDS) and Weissenberg reflection high energy electron diffraction (WRHEED).
Due to their very large quantum fluctuations, electron spins sometimes show quite intriguing and largely fluctuating ground states at low temperatures. Such fluctuating ground states may be enhanced by geometrical frustration, low dimensionality, and/or coupling to other degrees of freedom. We are aiming at understanding such fluctuation-dominated ground states, and also at finding novel macroscopic quantum phenomena due to the quantum fluctua- tions, using neutron inelastic scattering.
Crystal symmetries, microscopic crystal structures, atom positions, Debye-Waller factors and bonding charge distribution are studied by convergent-beam electron diffraction (CBED) and electron microscopy using an energy-filter transmission electron microscope...
Material science is one of the key word to consider the modern society, and the structural and crystal physics gives a fundamental base for this field.
The world's most advanced research data is often generated through state-of-the-art measurements, analysis techniques and instruments, and experimental techniques is evolving significantly. Understanding the physical behavior of these measurements, analysis techniques and actively will lead to new measurement and analysis methods that will open new frontiers both in physics and in the fusion of different fields.
