experimental condensed matter physics; surface science and nanoscience; scanning probe microscopy and spectroscopy; ultrafast nano-optics; nonlinear optics; 2D materials.

The goal of our research group is to search for microscopic understanding of important problems in condensed matter physics and surface science by developing and applying state-of-the-art scanning probe and optical techniques. The problems include atomic-scale understanding of photophysics, spectroscopy and dynamics in two-dimensional quantum materials, exotic physics in one dimensional or quasi-one dimensional nanostructures, phase transition and separation in complex oxides, low dimensional plasmonic structures. The techniques include scanning tunneling microscopy, atomic force microscopy, near-field and confocal scanning optical microscopy. Development of novel microscopic techniques are an integral part of our research efforts.

• Study of single molecules and nanostructures at surfaces and their response to light irradiation. In order to do that, we've been developing a laser-combined variable temperature scanning tunneling microscope in ultrahigh vacuum. These studies are expected to reveal elementary physical and chemical processes at surfaces and provide guidance in a number of applications such as photocatalysis, solar energy harvesting and photonic devices.
• Confocal and near-field optical imaging and spectroscopy of small objects at high spatial, spectral and temporal resolution. We are interested not only in novel nanostructures such as 2D transition metal dichalcogenides and graphene, but also in nanoscale inhomogeneous materials such as strongly correlated complex oxides. We will explore novel nanoscale phenomena and reveal their underlying physical mechanisms. Such studies would lead to the application of new materials and development of novel devices.
• Development of new scanning probe techniques to provide new capabilities and improve existing measurements. By combining other experimental techniques and theoretical methods, we would like to collaborate with others to solve fundamental problems in condensed matter physics and surface science.