Fabrication of a novel magnetic topological heterostructure and temperature evolution of its massive Dirac cone

新奇な磁気トポロジカル絶縁体ヘテロ構造の創製とそのディラックコーンの温度依存性

平原 徹*; Otrokov, M. M.*; 佐々木 泰祐*; 角田 一樹*; 友弘 雄太*; 日下 翔太郎*; 奥山 裕磨*; 一ノ倉 聖*; 小林 正起*; 竹田 幸治   ; 雨宮 健太*; 白澤 徹郎*; 出田 真一郎*; 宮本 幸治*; 田中 清尚*; 黒田 真司*; 奥田 太一*; 宝野 和博*; Eremeev, S. V.*; Chulkov, E. V.*

Hirahara, Toru*; Otrokov, M. M.*; Sasaki, Taisuke*; Sumida, Kazuki*; Tomohiro, Yuta*; Kusaka, Shotaro*; Okuyama, Yuma*; Ichinokura, Satoru*; Kobayashi, Masaki*; Takeda, Yukiharu; Amemiya, Kenta*; Shirasawa, Tetsuro*; Ideta, Shinichiro*; Miyamoto, Koji*; Tanaka, Kiyohisa*; Kuroda, Shinji*; Okuda, Taichi*; Hono, Kazuhiro*; Eremeev, S. V.*; Chulkov, E. V.*

We fabricate a novel magnetic topological heterostructure MnBiTe/BiTe where multiple magnetic layers are inserted into the topmost quintuple layer of the original topological insulator BiTe. A massive Dirac cone (DC) with a gap of 40-75 meV at 16 K is observed. By tracing the temperature evolution, this gap is shown to gradually decrease with increasing temperature and a blunt transition from a massive to a massless DC occurs around 200-250 K. Magnetic measurements show that there are two distinct Mn components in the system that corresponds to the two heterostructures; MnBiTe/BiTe is paramagnetic at 6 K while MnBiTe/BiTe is ferromagnetic with a negative hysteresis (critical temperature 20 K). This novel heterostructure is potentially important for future device applications.