Quantum spin transport in Rashba systems

2016 Fiscal Year Final Research Report

• Project/Area Number: 15H06133
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Single-year Grants
• Research Field: Condensed matter physics I
• Research Institution: The University of Tokyo
• Principal Investigator: Ideue Toshiya 東京大学, 大学院工学系研究科(工学部), 助教 (90757014)
• Project Period (FY): 2015-08-28 – 2017-03-31
• Keywords: 非相反電荷輸送現象 / 空間反転対称性の破れ / スピン軌道相互作用 / 極性 / ラシュバ系 / カイラリティー

Outline of Final Research Achievements

In this research, we have studied the nonreciprocal electric transport in polar and chiral materials, which is one of the manifestations of the lattice symmetry breaking in electric transport.
We have successfully observed the second harmonic signals of resistance under magnetic field in polar semiconductor BiTeBr. The observed nonlinear signals correspond to the bulk rectification and satisfy the characteristic selection rule for polar systems. In addition, the experimental results can be quantitatively explained by the simple model using the three-dimensional Rashba model.
We further observed the nonreciprocal electric transport in chiral WS2 nanotubes. Nonreciprocal electric transport is largely enhanced in electric-field-induced superconducting state. Periodic oscillations observed both in first and second harmonic signals indicate that nonreciprocal superconducting transport is affected by the characteristic cylindrical geometry.

Free Research Field

固体物理学