We have obtained angle-resolved photoemission spectroscopy (ARPES) spectra from single crystals of the topological insulator material Bi2Te3 using a tunable laser spectrometer. The spectra were collected for 11 different photon energies ranging from 5.57 to 6.70 eV for incident light polarized linearly along two different in-plane directions. Parallel first-principles, fully relativistic computations of photointensities were carried out using the experimental geometry within the framework of the one-step model of photoemission. A reasonable overall accord between theory and experiment is used to gain insight into how properties of the initial- and final-state band structures as well as those of the topological surface states and their spin textures are reflected in the laser-ARPES spectra. Our analysis reveals that laser-ARPES is sensitive to both the initial-state kz dispersion and the presence of delicate gaps in the final-state electronic spectrum.
Available at: http://works.bepress.com/thomas_lograsso/248/
This article is published as Ärrälä, Minna, Hasnain Hafiz, Daixiang Mou, Yun Wu, Rui Jiang, Trevor Riedemann, Thomas A. Lograsso, Bernardo Barbiellini, Adam Kaminski, Arun Bansil, and Matti Lindroos. "Laser angle-resolved photoemission as a probe of initial state k z dispersion, final-state band gaps, and spin texture of Dirac states in the Bi 2 Te 3 topological insulator." Physical Review B 94, no. 15 (2016): 155144. DOI: 10.1103/PhysRevB.94.155144. Posted with permission.