2017/09/30 by Pedro Roman-Taboada, Gerardo G Naumis, Gerardo G. Naumis
Materials Science · Physics and Astronomy · #Geometric phase #Graphene nanoribbons #Graphene research and applications #Hamiltonian (control theory) #Phase diagram #Quantum Mechanics and Non-Hermitian Physics #Topological Materials and Phenomena #Topology (electrical circuits) #Type (biology) #Winding number #Zigzag #cond-mat.mes-hall
paper · pdf · doi:10.1088/2399-6528/aa98fd
12 pages, 7 figures, 2 appendices. Some issues with the text were corrected. Additional information about the experimental realization of our model and two figures were included for the sake of clarity. Comments and suggestions are welcome. The manuscript is to appear on Journal of Physics Communications
arxiv created 2017/12/02 · openalex publication_date 2017/12/21 · openalex created_date 2017/12/22 · arxiv updated 2017/12/25 · openalex updated_date 2026/08/06
The topological properties of electronic edge states in time-periodically driven spatially-periodic corrugated zigzag graphene nanoribbons are studied. An effective one-dimensional Hamiltonian is used to describe the electronic properties of graphene and the time-dependence is studied within the Floquet formalism. Then the quasienergy spectrum of the evolution operator is obtained using analytical and numeric calculations, both in excellent agreement. Depending on the external parameters of the time-driving, two different kinds (types I and II) of touching band points are found, which have a Dirac-like nature at both zero and quasienergy. These touching band points are able to host topologically protected edge states for a finite size system. The topological nature of such edge states was confirmed by an explicit evaluation of the Berry phase in the neighborhood of type I touching band points and by obtaining the winding number of the effective Hamiltonian for type II touching band points. Additionally, the topological phase diagram in terms of the driving parameters of the system was built.