Real-space investigation of valley state of spin-valley coupled transition metal dichalcogenides

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K17730
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Condensed matter physics I
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Machida Tadashi 国立研究開発法人理化学研究所, 創発物性科学研究センター, 特別研究員 (60570695)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: バレートロ二クス / スピントロ二クス / 遷移金属ダイカルコゲナイド / 走査型トンネル顕微鏡

Outline of Final Research Achievements

We have performed Scanning tunneling microscopy and spectroscopy experiments on spin-valley coupled transition metal dichalcogenides, to investigate the role of not only spin but also orbital degrees of freedom (DOF) on the intra- and inter-valley scattering process. Our experimental results reveal that the signals of the inter-valley scattering are noticeably weaker than those of the intra-valley scattering. To understand the role of spin and orbital DOF on QPI, we performed theoretical simulations with only the spin selection rules and with the selection rules of both DOF. A comparison with the theoretical simulations indicate the necessity of the orbital selection rules to reproduce the observed suppression of inter-valley signals. These findings will provide important information in future application for valleytronics.

Free Research Field

semiconductor