Topological metal at the surface of an ultrathin Bi1-xSbx alloy film

被引：51

作者：

Hirahara, T. ^{[1
]}

Sakamoto, Y. ^{[1
]}

Saisyu, Y. ^{[1
]}

Miyazaki, H. ^{[2
]}

Kimura, S. ^{[2
]}

Okuda, T. ^{[3
]}

Matsuda, I. ^{[3
]}

Murakami, S. ^{[4
]}

Hasegawa, S. ^{[1
]}

机构：

[1] Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan

[2] Natl Inst Nat Sci, Inst Mol Sci, UVSOR Facil, Okazaki, Aichi 4448585, Japan

[3] Univ Tokyo, ISSP, Synchrotron Radiat Lab, Kashiwa, Chiba 2778581, Japan

[4] Tokyo Inst Technol, Dept Phys, Tokyo 1528551, Japan

来源：

PHYSICAL REVIEW B | 2010年 / 81卷 / 16期

关键词：

INSULATOR;

D O I：

10.1103/PhysRevB.81.165422

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have studied the growth and electronic/transport properties of ultrathin Bi1-xSbx alloy films, which the bulk is reported to be a topological insulator for 0.07 < x < 0.22. We found that single crystal epitaxial films as thin as similar to 30 angstrom could be grown on silicon for 0 <= x < 0.32. The Z(2) topological number of the films was shown to be nontrivial from the surface Fermi surface. Moreover a crossover from an insulating to a metallic behavior was observed upon reducing the film thickness, revealing the clear detection of the topological-metal conductivity. Our results settle the controversial issues concerning the metallicity of Bi1-xSbx at low temperature and verify that the surface/volume ratio must be extensively enhanced to properly understand the nature of these surface states.

引用

页数：5