Quasiparticle Energy and Excitons in Two-dimensional Structures

Download or read book Quasiparticle Energy and Excitons in Two-dimensional Structures written by Yufeng Liang and published by . This book was released on 2014 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-dimensional materials, such as graphene-related structures, transition metal dichalcogenides, are attracting enormous interest in nowadays condensed matter physics. They not only serve as ideal testbeds for rich physics in reduced-dimensional electron systems but are also of particular importance in nanoelectronic technology. Their electronic, transport, and optical properties are largely determined by the nature of excited states, such as quasiparticles and excitons. Understanding how these excited states emerge from a many-electron system is an intriguing intellectual process, which gives insight into experimental observation and sheds light on manipulating the materials' properties. From this aspect, it is highly desirable to introduce many-body perturbation theories, which do not rely on data from experiments, to study these excited-state properties and their relations to experimental measurements.In thisthesis, I will present a comprehensive study on a variety of two-dimensional materials using first-principles calculation with many-body effects taken into account. Particular attention is given to the impact of electrical gating, stacking order, and doping on the quasiparticle and excitonic properties.