Optical Study of Inter-band Transitions in Topological Insulators Bi2Se3, Bi2Te3, and Sb2Te3

Download or read book Optical Study of Inter-band Transitions in Topological Insulators Bi2Se3, Bi2Te3, and Sb2Te3 written by Pan P. Adhikari and published by . This book was released on 2017 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topological insulators are new states of quantum matter having their bulk as insulator but strange conducting properties present at their boundaries: edges (2D) and surfaces (3D). This is a blossoming research topic in condensed matter physics at the present time. They are thought to provide an excellent method for the realization of fault-tolerant quantum computing. We studied the optical properties and inter-band transitions of 3D topological insulators Bi2Se3, Bi2Te3, and Sb2Te3 by measuring the reflectivity using a UV-Visible spectrophotometer. In this work, we use the Drude-Lorentz model to fit the experimental data in the infrared, visible and ultraviolet regions of radiation (30-50,000 cm−1) and compare the reflectivity and optical conductivity for the three samples. Our results show that, in all three materials there are inter-band transitions: one major transition in Bi2Se3 and Sb2Te3, and two in Bi2Te3. These inter-band transitions cause relatively higher reflectivity R(w) values (-̃50%) in the visible region. Our results might be useful in the practical applications of topological insulators especially in laser applications.