著者
横山 毅人 田仲 由喜夫
出版者
公益社団法人 日本表面科学会
雑誌
表面科学 (ISSN:03885321)
巻号頁・発行日
vol.32, no.4, pp.202-208, 2011-04-10 (Released:2011-04-19)
参考文献数
50

We study charge transport on the surface state of topological insulator where two-dimensional Dirac electron is generated. We put ferromagnetic insulator or superconductor on the topological insulator and reveal anomalous charge transport on the surface. We first consider the charge transport through a ferromagnetic insulator/ferromagnetic insulator (FI/FI) junction on a topological insulator. The resulting conductance across the interface depends sensitively on the directions of the magnetizations of the two FI, showing anomalous behaviors compared with the conventional spin valve. It is found that the conductance depends strongly on the in-plane direction of the magnetization. Moreover, in sharp contrast to the conventional magnetoresistance effect, the conductance at the parallel configuration can be much smaller than that at the antiparallel configuration. We also study the transport properties of a normal metal (N)/FI/superconductor (S) junction formed on the surface of a three-dimensional topological insulator, where chiral Majorana edge mode exists at the FI/S interface. We find that the chiral Majorana edge mode generated in N/FI/S junction strongly influences the charge conductance.
著者
土浦 宏紀 小形 正男 田仲 由喜夫 柏谷 聡
出版者
一般社団法人 日本物理学会
雑誌
日本物理学会誌 (ISSN:00290181)
巻号頁・発行日
vol.58, no.4, pp.254-257, 2003-04-05 (Released:2008-04-14)
参考文献数
18

銅酸化物超伝導体中に不純物原子をドープすると,そのまわりに準粒子の束縛状態が形成される.走査型トンネル顕微鏡技術の進歩と相俟って,この生活状態の理解がここ数年で飛躍的に進んだ.本稿では,もっとも理解の進んでいるZn不純物近傍の束縛状態について,実験結果とその理論的解釈を紹介する.