Satoshi Iwamoto

Creation of topological integrated photonic devices

Grant No.：JPMJCR19T1

Research Director

Satoshi Iwamoto

Collaborator

Nobukiyo Kobayashi	Director Research ＆ Development Department,Department of Creation of New Materials Research Institute for Electromagnetic Materials
Shun Takahashi	Associate Professor Electrical Engineering and Electronics Kyoto Institute of Technology

Outline

By fusing integrated photonics technology and the concept of topology, we will realize novel topological integrated photonic devices such as unidirectional waveguides using a chiral edge state at telecommunication wavelengths, skyrmion lasers, and so on. We will also realize various topological states of light by fully taking the advantages of integrated photonics technology and explore their potential applications. Through these studies, we will form a mutual link between topological science and photonics, and contribute to the creation of new optical technologies and the progress in topological science.

Yasuyuki Kawahigashi

Theoretical studies of topological phases of matter

Grant No.：JPMJCR19T2

Research Director

Yasuyuki Kawahigashi

Collaborator

Masatoshi Sato	Professor Yukawa Institute for Theoretical Physics Kyoto University
Akira Furusaki	Chief Scientist Cluster for Pioneering Research RIKEN

Outline

Effectiveness of mathematical methods in studies of topological phases is clear, but we have not grasped their total pictures. In this project, mathematicians and theoretical physicists work together to establish universal theory of topological phases aimed at a wide range of systems of matter and give a basis of development of materials and devices in new dimensions. We believe this study will be useful for research of mathematical and physical fundamental theories of topological quantum computers.

Ryo Shimano

New Developments of Topological Nonlinear Optics

Grant No.：JPMJCR19T3

Research Director

Ryo Shimano

Collaborator

Takashi Oka	Professor The Institute for Solid State Physics The University of Tokyo
Masamitsu Hayashi	Associate Professor Graduate School of Science The University of Tokyo
Takahiro Morimoto	Associate Professor School of Engineering The University of Tokyo

Outline

We investigate nonlinear optical responses that arise from the topological phase (Berry phase) of electrons in quantum materials for their application to the novel photo electronics. Circular photo-galvanic effect and shift current in topological materials will be studied by combining the transport and optical measurements. With aid of Floquet engineering, the fundamental concept of topological nonlinear optics will be extended to spin-current phenomena, nonlinear optics in superconductors and strongly correlates electron systems.

Tetsuo Deguchi

Innovative topological theory of polymer elasticity based on homology and its application to molecular devices through ring-polymer mixture

Grant No.：JPMJCR19T4

Research Director

Tetsuo Deguchi

Collaborator

Toshifumi Sato	Professor Faculty of Engineering Hokkaido University
Hiroshi Jinnai	Professor Institute of Multidisciplinary Research for Advanced Materials Tohoku University

Outline

In terms of homology theory we reconstruct the elastic theory of polymer networks at the fundamental level. We present a theoretical method for exactly evaluating the elastic constant of any given Gaussian polymer network from its network structure. Applying it, we study systematically the mechanical responses of various gels and rubbers. We synthesize ring polymers and mix them with linear polymers to make novel elastic materials in which ring polymers would act mobile junctions. Scattering experiments, mechanical measurements based on rheology and strain stress curves, and 3D observations through electron microscopes will be performed on the mixtures of ring and linear polymers. Based on such knowledge, we aim to derive molecular devices as engineering applications.

Yuji Matsuda

Direct detection of topological quasiparticles in a quantum spin liquid

Grant No.：JPMJCR19T5

Research Director

Yuji Matsuda

Collaborator

Takasada Shibauchi	Professor Graduate School of Frontier Sciences The University of Tokyo
Satoshi Fujimoto	Professor Department of Materials Engineering Science Osaka University

Outline

Majorana fermions and non-Abelian anyons originating from topological structures of materials are key particles for realizing fault-tolerant topological quantum computing. Recently, it has been demonstrated that insulating magnets in a Kitaev quantum spin liquid state (Kitaev magnets) host these emergent topological quasiparticles. We will thoroughly clarify the fundamental topological properties of the Kitaev magnets and explore novel electronic phases, such as topological superconductivity. Moreovre, we will establish the technique for topological quantum computing by direct detection and visualization of the emergent topological quasiparticles.