CVClient

草部 浩一

クサカベ コウイチ  (Koichi Kusakabe)

基本情報

所属
兵庫県立大学 理学研究科 物質科学専攻 教授
大阪大学 基礎工学研究科 物質創成専攻 准教授
学位
理学博士(東京大学)
理学修士(東京大学)

J-GLOBAL ID
200901089608768091
researchmap会員ID
1000185126

研究キーワード

 4

論文

 177
  • Keiki Fukumoto, Seunghee Lee, Shin-ichi Adachi, Yuta Suzuki, Koichi Kusakabe, Rikuto Yamamoto, Motoharu Kitatani, Kunio Ishida, Yoshinori Nakagawa, Michael Merkel, Daisuke Shiga, Hiroshi Kumigashira
    Scientific Reports 14(1) 2024年5月8日  
    Abstract Topological insulators (TI) hold significant potential for various electronic and optoelectronic devices that rely on the Dirac surface state (DSS), including spintronic and thermoelectric devices, as well as terahertz detectors. The behavior of electrons within the DSS plays a pivotal role in the performance of such devices. It is expected that DSS appear on a surface of three dimensional(3D) TI by mechanical exfoliation. However, it is not always the case that the surface terminating atomic configuration and corresponding band structures are homogeneous. In order to investigate the impact of surface terminating atomic configurations on electron dynamics, we meticulously examined the electron dynamics at the exfoliated surface of a crystalline 3D TI (Bi$$_2$$Se$$_3$$) with time, space, and energy resolutions. Based on our comprehensive band structure calculations, we found that on one of the Se-terminated surfaces, DSS is located within the bulk band gap, with no other surface states manifesting within this region. On this particular surface, photoexcited electrons within the conduction band effectively relax towards DSS and tend to linger at the Dirac point for extended periods of time. It is worth emphasizing that these distinct characteristics of DSS are exclusively observed on this particular surface.
  • 草部浩一
    まぐね/Magnetics Jpn. 19(2) 80-88 2024年4月  査読有り筆頭著者
  • Yasuhiro Oishi, Motoharu Kitatani, Koichi Kusakabe
    Beilstein Journal of Organic Chemistry 20 570-577 2024年3月11日  
    We theoretically analyze possible multiple conformations of protein molecules immobilized by 1-pyrenebutanoic acid succinimidyl ester (PASE) linkers on graphene. The activation barrier between two bi-stable conformations exhibited by PASE is confirmed to be based on the steric hindrance effect between a hydrogen on the pyrene group and a hydrogen on the alkyl group of this molecule. Even after the protein is supplemented, this steric hindrance effect remains if the local structure of the linker consisting of an alkyl group and a pyrene group is maintained. Therefore, it is likely that the kinetic behavior of a protein immobilized with a single PASE linker exhibits an activation barrier-type energy surface between the bi-stable conformations on graphene. We discuss the expected protein sensors when this type of energy surface appears and provide a guideline for improving the sensitivity, especially as an oscillator-type biosensor.
  • Halimah Harfah, Yusuf Wicaksono, Gagus Ketut Sunnardianto, Muhammad Aziz Majidi, Koichi Kusakabe
    Physical Chemistry Chemical Physics 26(12) 9733-9740 2024年3月6日  
    Enhanced spin control in graphene/hBN MTJ: boron vacancy tuning yields high TMR ratio of 400%, paving the way for ultra-thin spin valves.
  • 草部浩一
    まぐね/Magnetics Jpn. 18(6) 287-294 2023年12月  査読有り筆頭著者

MISC

 270

書籍等出版物

 5

共同研究・競争的資金等の研究課題

 37