Cyclotron resonance study of Dirac electron state in topological insulator

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400335
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: Kobe University
• Principal Investigator: Okubo Susumu 神戸大学, 分子フォトサイエンス研究センター, 准教授 (80283901)
• Research Collaborator: Sasagawa Takao ; Ikeda Shohei ; Yoshida Shota
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: トポロジカル絶縁体 / サイクロトロン共鳴 / 高周波数 / 強磁場 / フェルミ面 / ディラック電子状態

Outline of Final Research Achievements

Recently topological insulator as a peculiar surface state is proposed theoretically. Although bulk state is insulator due to existence of a energy gap between valence and conduction bands, metal state realized in surface due to close energy gap. Aim of this study is direct measurements of Dirac electron state in topological insulator, which was considered that surface electrons have linear dispersion of energy, by cyclotron resonance of transmission method. For this purpose, we developed a high sensitive measurement system using a short length cryostat and a high resolution acquisition digital storage oscilloscope. Developed system becomes 20 times higher sensitivity than precedent system. Cyclotron resonance measurements of bundled thin films of topological insulator Bi2Se3 have been performed. Intrinsic signals of cyclotron resonance were observed in low frequency region. However, we cannot estimate the Fermi velocity due to lack of sensitivity in high frequency region.

Free Research Field

強磁場物性