Objectives of the project
Focusing on topological nature of materials, we aim to explore novel quantum phenomena driven by interaction, symmetry of crystals and nanostructure of semiconductors, and search for exotic quasiparticles inherent in the topological quantum phenomena, thereby elucidating the underlying physics behind them.
Recent years have seen a tremendous growth of interest in topological quantum phenomena. However, quite a few issues still remain unexplored. In particular, (1) clarifying effects of interactions between electrons which would lead to diversity and functionality of materials, (2) exploring topological materials based on symmetry of crystals, and (3) systematic control of artificial topological phases in nanostructured systems, are indispensable for developing novel materials and establishing the fundamental concepts. This project systematically studies these issues at the frontiers of materials science.
This project consists of four core projects:
A: Topology and Correlation
B: Topology and Symmetry
C: Topology and Nanoscience
D: Topology and New Concepts
The core projects A, B and C respectively investigate strongly correlated systems, semiconductor systems and nanostructured systems. The core project D, theory group, aims to develop new concepts and stimulates collaborations among A-C. We also have some theorists in A-C, who will do research in intimate collaboration with experimentalists.
Research issue A: Topology and Symmetry
The purpose of this core project is to investigate topologically non-trivial quantum condensates and quantum phase transitions in superconductors, insulators, semimetals, etc. with strong interactions between electrons (strongly correlated electron systems), and thereby deepen and develop the research in topological materials science.
In this core project, we choose transition metal oxides and heavy electron compounds as the main stages of correlated materials, and investigate topological quantum phenomena in systems including artificial superlattices, nanostructures, and junctions. Through this research, we attempt to re-examine the conventional classification of "unconventional superconductivity" from the new viewpoint of topological superconductivity. In addition, we will create and control novel topological phases emerging from Mott insulators and semimetals, and clarify the roles of electron correlations. We will conduct these researches utilizing active collaborations with other core research projects as well as with open-solicitation projects.