Nonlinear Optical Probe of Tunable Surface Electrons on a Topological Insulator

被引：128

作者：

Hsieh, D. ^{[1
]}

McIver, J. W. ^{[1
,2
]}

Torchinsky, D. H. ^{[1
]}

Gardner, D. R. ^{[1
]}

Lee, Y. S. ^{[1
]}

Gedik, N. ^{[1
]}

机构：

[1] MIT, Dept Phys, Cambridge, MA 02139 USA

[2] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA

来源：

PHYSICAL REVIEW LETTERS | 2011年 / 106卷 / 05期

关键词：

SINGLE DIRAC CONE; 2ND-HARMONIC GENERATION; TRANSPORT; BI2SE3;

D O I：

10.1103/PhysRevLett.106.057401

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We use ultrafast laser pulses to experimentally demonstrate that the second-order optical response of bulk single crystals of the topological insulator Bi2Se3 is sensitive to its surface electrons. By performing surface doping dependence measurements as a function of photon polarization and sample orientation we show that second harmonic generation can simultaneously probe both the surface crystalline structure and the surface charge of Bi2Se3. Furthermore, we find that second harmonic generation using circularly polarized photons reveals the time-reversal symmetry properties of the system and is surprisingly robust against surface charging, which makes it a promising tool for spectroscopic studies of topological surfaces and buried interfaces.

引用

页数：4

共 27 条

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