Current Research
Surfaces of materials such as semiconductors, metals, and topological insulators, are platforms of our research where rich physics is expected due to the low-dimensionality and symmetry breakdown. (1) Electronic/spin/mass transports, (2) atomic/electronic structures, (3) phase transitions, (4) electronic excitations, (5) spin states and magnetism, and (6) epitaxial growths of coherent atomic/molecular layers/wires on surfaces, topological surfaces, and nano-scale phases such as surface superstructures, ultra-thin films such as graphene and silicene. We use various kinds of ultrahigh vacuum experimental techniques, electron diffraction, scanning electron microscopy, scanning tunneling microscopy/spectroscopy (STM/S), photoemission spectroscopy, in-situ four-point-probe conductivity measurements with four-tip STM and monolithic micro-four-point probes, and surface magneto-optical Kerr effect measurements.