2012/09/30 by Jing Wang, Hideo Mabuchi, Xiao-Liang Qi
Engineering · Materials Science · Physics and Astronomy · #Absorption (acoustics) #Band gap #Condensed matter physics #Geometry #Graphene research and applications #Insulator (electricity) #Materials science #Nanophotonics #Nonlinear Optical Materials Studies #Nonlinear optics #Nonlinear system #Optics #Optoelectronics #Photon #Photon energy #Physics #Quantum mechanics #Substrate (aquarium) #Surface (topology) #Surface states #Topological Materials and Phenomena #Topological insulator #Topology (electrical circuits) #Two-photon absorption #cond-mat.mes-hall #cond-mat.mtrl-sci #quant-ph
paper · pdf · doi:10.1103/physrevb.88.195127
published as Phys. Rev. B 88, 195127 (2013) · 6 pages, 3 figures
arxiv created 2013/11/15 · openalex publication_date 2013/11/15 · arxiv updated 2013/11/18 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We perform linear and nonlinear photon absorption calculations in ultrathin films of a topological insulator on a substrate. Due to the unique band structure of the coupled topological surface states, novel features are observed for suitable photon frequencies, including a divergent edge singularity in the one-photon absorption process and a significant enhancement in the two-photon absorption process. The resonant frequencies can be controlled by tuning the energy difference and coupling the top and bottom surface states. Such unique linear and nonlinear optical properties make ultrathin films of topological insulators promising material building blocks for tunable high-efficiency nanophotonic devices.