Surface Electronic Structure of Cr Doped Bi<sub>2</sub>Se<sub>3</sub> Single Crystals

oleh: Turgut Yilmaz, Xiao Tong, Zhongwei Dai, Jerzy T. Sadowski, Genda Gu, Kenya Shimada, Sooyeon Hwang, Kim Kisslinger, Elio Vescovo, Boris Sinkovic

Format: Article
Diterbitkan: MDPI AG 2024-09-01

Deskripsi

Here, by using angle-resolved photoemission spectroscopy, we showed that Bi<sub>2−x</sub>Cr<sub>x</sub>Se<sub>3</sub> single crystals have a distinctly well-defined band structure with a large bulk band gap and undistorted topological surface states. These spectral features are unlike their thin film forms in which a large nonmagnetic gap with a distorted band structure was reported. We further provide laser-based high resolution photoemission data which reveal a Dirac point gap even in the pristine sample. The gap becomes more pronounced with Cr doping into the bulk of Bi<sub>2</sub>Se<sub>3</sub>. These observations show that the Dirac point can be modified by the magnetic impurities as well as the light source.