RESEARCH

Before the discovery of high-Tc superconductors, no attention has been paid for the the effect of the anisotropy of the pair potential on the tunneling effects of superconductors. Through the tunneling spectroscopic studies of high-Tc superconductors, we discovered the formation of novel Andreev bound states (ABS) at the surfaces of d-wave superconductor and clarified the serious influences of the ABS on the transport properties of tunneling junctions. We succeeded in the detection of the zero-energy ABS at the edge of high-Tc oxides, and also the dispersive edge states at the in-plane surface of Sr₂RuO₄. These observations reveal the topological superconductivity of high-Tc oxides and Sr₂RuO₄.

The aim of the present project is to establish unambiguously the topological superconductivity of Sr₂RuO₄ using phase sensitive measurements. We are planning to apply similar phase sensitive measurements for various types of candidate materials of topological superconductors. We hope to reveal the presence of the majorana fermions and their non-Abelian statistics in topological superconductors so as to present the high potential of the topological superconductors for the quantum computation.

EDUCATION

1988

Master degree, Department of Mathematical Engineering and Instrumentation Physics, School of Engineering, The University of Tokyo

1996

Ph.D Physics, The University of Tokyo

PROFESSIONAL EXPERIENCE

1988-1995

Research associate, Electrotechnical Laboratory, Agency of Industrial Science and Technology

1995-2001

Chief researcher, Electrotechnical Laboratory, Agency of Industrial Science and Technology

2001-2003

Leader, Low-temperature physics Group, Nanoelectronics Research Institute, Advance Industrial Science and Technology

2003-2018

Senior Research Scientist, Electronics and Photonics Research Institute, National Institute of Advanced Industrial Science and Technology

2018-Present

Professor, Department of Applied Physics, Nagoya University

HONORS AND AWARDS

2000

Japan IBM Science Award

2005

Superconductivity Science and Technology Award

SELECTION OF PUBLICATIONS

"Imaging of current density distributions with a Nb weak-link scanning nano-SQUID microscope"
Y. Shibata, S. Nomura, H. Kashiwaya, S. Kashiwaya, R. Ishiguro, and H. Takayanagi,
Scientific Reports 5, 15097-1-10 (Oct. 2015)
DOI: 10.1038/srep15097

"Inversion symmetry of Josephson current as test of chiral domain wall motion in Sr₂RuO₄"
K. Saitoh, S. Kashiwaya, H. Kashiwaya, Y. Mawatari, Y. Asano, Y. Tanaka, and Y. Maeno,
Physical Review B 92, 100504-1-6 (Sep. 2015)
DOI: 10.1103/PhysRevB.92.100504

"Circularly Polarized Near-Field Optical Mapping of Spin-Resolved Quantum Hall Chiral Edge States"
S. Mamyouda, H. Ito, Y. Shibata, S. Kashiwaya, M. Yamaguchi, T. Akazaki, H. Tamura, Y. Ootuka, and S. Nomura,
Nano Letters 15 2417–2421 (Apr. 2015)
DOI: 10.1021/nl504767w

"Tunneling spectroscopy of topological superconductors"
S. Kashiwaya, H. Kashiwaya, K. Saitoh, Y. Mawatari, Y.Tanaka,
Physica E 55, 25-29 (Jan. 2014).
DOI: 10.1016/j.physe.2013.07.016

"Anomalous Josephson current in superconducting topological insulator"
A. Yamakage, M. Sato, K. Yada, S. Kashiwaya, and Y. Tanaka,
Physical Review B 87, 100510-1-5 (Mar. 2013).
DOI: 10.1103/PhysRevB.87.100510

"High-Supercurrent-Density Contacts and Josephson Effect of Strontium Ruthenate"
K. Saitoh, S. Kashiwaya, H. Kashiwaya, M. Koyanagi, Y. Mawatari, Y. Tanaka, Y. Maeno,
Applied Physics Express 5, 113101-1-5 (Oct. 2012).
DOI: 10.1143/APEX.5.113101

"Near-Field Optical Mapping of Quantum Hall Edge States"
H. Ito, K. Furuya, Y. Shibata, S. Kashiwaya, M. Yamaguchi, T. Akazaki, H. Tamura, Y. Ootuka, S. Nomura,
Physical Review Letters 107, 256803-1-5 (Dec. 2011).
DOI: 10.1103/PhysRevLett.107.256803

"Edge States of Sr₂RuO₄ Detected by In-Plane Tunneling Spectroscopy"
S. Kashiwaya, H. Kashiwaya, H. Kambara, T. Furuta, H. Yaguchi, Y. Tanaka, Y. Maeno,
Physical Review Letters 107, 077003-1-4 (Aug. 2011).
DOI: 10.1103/PhysRevLett.107.077003

"Tunneling effects on surface bound states in unconventional superconductors"
S. Kashiwaya and Y. Tanaka,
Report on Progress on Physics. 63, 1641-1-85 (Oct. 2000).
http://iopscience.iop.org/article/10.1088/0034-4885/63/10/202/meta

"Switching Dynamics of Bi₂Sr₂CaCu₂O_8+d Intrinsic Josephson Junctions: Macroscopic Quantum Tunneling and Self-Heating Effect"
H. Kashiwaya, T. Matsumoto, H. Shibata,S. Kashiwaya, H. Eisaki, Y. Yoshida,
S. Kawabata and Y. Tanaka,
Journal of Physical Society of Japan. 77, 104708-1-8 (Oct. 2008).
DOI: 10.1143/JPSJ.77.104708

"Anomalous Transport through the p-Wave Superconducting Channel in the 3-K Phase of Sr₂RuO₄"
H. Kambara, S. Kashiwaya, H. Yaguchi, Y. Asano, Y. Tanaka, and Y. Maeno,
Physical Review Letters. 101, 267003-1-4 (Dec. 2008).
DOI: 10.1103/PhysRevLett.101.267003