Electronic Structure of the Topological Insulator Bi[subscript 2]Se[subscript 3] Using Angle-Resolved Photoemission Spectroscopy: Evidence for a Nearly Full Surface Spin Polarization

• Main Authors: Pan, Z.-H (Author), Vescovo, E. (Author), Fedorov, A. V. (Author), Gardner, Dillon Richard (Contributor), Lee, Young S. (Contributor), Chu, Shaoyan (Contributor), Gu, G. D. (Author), Valla, T. (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering (Contributor), Massachusetts Institute of Technology. Department of Physics (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2011-09-29T14:15:44Z.
• Subjects: Article
• Online Access: Get fulltext

 We performed high-resolution spin- and angle-resolved photoemission spectroscopy studies of the electronic structure and the spin texture on the surface of Bi[subscript 2]Se[subscript 3], a model TI. By tuning the photon energy, we found that the topological surface state is well separated from the bulk states in the vicinity of kz=Z plane of the bulk Brillouin zone. The spin-resolved measurements in that region indicate a very high degree of spin polarization of the surface state, ∼0.75, much higher than previously reported. Our results demonstrate that the topological surface state on Bi[subscript 2]Se[subscript 3] is highly spin polarized and that the dominant factors limiting the polarization are mainly extrinsic.