1303.0698 (Zhuojin Xie et al.)

Direct Observation and Manipulation of Spin-Orbital Texture in a
Topological Insulator    [PDF]

Zhuojin Xie, Shaolong He, Chaoyu Chen, Ya Feng, Hemian Yi, Aiji Liang, Lin Zhao, Daixiang Mou, Junfeng He, Yingying Peng, Xu Liu, Yan Liu, Guodong Liu, Xiaoli Dong, Jun Zhang, Xiaoyang Wang, Qinjun Peng, Zhimin Wang, Shenjin Zhang, Feng Yang, Chuangtian Chen, Zuyan Xu, X. J. Zhou

Topological insulators represent a new quantum state of matter that are insulating in the bulk but metallic on the surface possessing unique electronic structure and spin texture. The electrons in the Dirac surface state are highly polarized and their spin is locked with the crystal momentum. Here we report direct observation of the spin-orbital texture in the Bi2Se3 topological insulator. The spin texture of the Bi2Se3 surface state has been directly measured by high resolution spin- and angle-resolved photoemission spectroscopy. Different orbitals in Bi2Se3 have been selectively probed using variable polarization of the incident light. We have observed distinct spin textures under different light polarization geometries that constitute strong evidence of the spin-orbital texture in Bi2Se3. The observation of the spin texture locking with the orbital texture provides an additional degree of freedom in controlling the spin structure in the topological insulators. It also demonstrates the feasibility on the light manipulation of the orbital-selective spin texture of the topological insulators that is important for their future applications in spin-related technologies.

View original: http://arxiv.org/abs/1303.0698