分子科学研究所

Site Search

About IMS

Research

Graduate University

Life@Okazaki

Access   Researchers List   Publication
Contact
Japanese

Research

Seminar & Events

IMS Researchers

HOME - Research - Seminar & Events - Detail
Research

Seminar & Events Detail

Open seminar

Lecture Title "Supercurrent induced by spin-orbit interaction in two- and multi-terminal Josephson junctions"
Date Thursday 1 October 2015 15:00
Lecturer Tomohiro Yokoyama （JSPS Postdoctoral Fellow for Research Abroad Kavli institute of Nanoscience,Delft University of Technology）
Place

Institute for Molecular Science, Research Building, Seminar Room, #201
Summary

Many phenomena based on the spin-orbit (SO) interaction are studied recently, e.g., Majorana fermion. In this talk, we study the Josephson junction in semiconductor nanostructures with strong SO interaction. Suchstrong SO interaction is observed in InSb, InAs, etc. First, we study the DC Josephson effect with SO interaction in InSb nanowires. The DC Josephson current is evaluated from the energy of Andreev bound states in the case of short junctions. The SO interaction and Zeeman effect breaks the symmetry of Andreev levels, which results in the anomalous Josephson current even at no phase difference. We reveal the origin of anomalous Josephson effect by analytical and numerical calculations. Moreover, the SO interaction induces the magnetic anisotropy of critical current. The anisotropy enables to evaluate the direction of effective SO field in the nanowire. Next, we consider multi-terminal Josephson junction with N (> 2) superconductors. The Andreev bound states forms the ‘band structure’ in N-1 phase space. In some junctions, we find accidental point touching of Andreev levels at zero energy, which indicates conical corn like as the Dirac corn. We investigate the Dirac and Weyl (like) physics in Josephson junction.

 

[1] Yokoyama, Eto, and Nazarov, JPSJ 82, 054703 (2013)
[2] Yokoyama, Eto, and Nazarov, PRB 89, 195407 (2014)
[3] Yokoyama and Nazarov, EPL 108, 47009 (2014)
[4] Yokoyama and Nazarov, arXiv: 1508.00146
Contact

Yutaka Shikano
Awards & Honors International collaboration

Links

英_TILAコンソーシアム