AVS 58th Annual International Symposium and Exhibition
    Graphene and Related Materials Focus Topic Tuesday Sessions
       Session GR+EM-TuM

Paper GR+EM-TuM4
Quantum Mechanics-Based Exploration of Graphene-Like Systems to Model Magnetic Resonators

Tuesday, November 1, 2011, 9:00 am, Room 208

Session: Graphene: Optical Properties, Optoelectonics and Photonics
Presenter: Dimitrios Papaconstantopoulos, George Mason University
Authors: X.W. Sha, George Mason University
E.N. Economou, George Mason University
D.A. Papaconstantopoulos, George Mason University
M.R. Pederson, Naval Research Laboratory
M.J. Mehl, Naval Research Laboratory
M. Kafesaki, University of Crete, Greece
Correspondent: Click to Email
Quasi-circular pieces of graphene as well as nanotubes offer the possibility of acting as magnetic resonators to be used in negative refractive index optical metamaterials. The advantage of these graphene pieces is twofold: (a) they are stable even when their size reaches the tens of nanometers; (b) the induced currents in the presence of an AC magnetic field perpendicular to the graphene plane cancel each other in all the interior hexagons and only an edge circular current remains. This current is expected to be ballistic in nature with almost zero resistance. This analog of the split (in the split ring resonators) is expected to be achieved by the substitutional insertion of foreign atoms (e.g. nitrogen atoms). To explicitly and reliably check these ideas we have used the NRLMOL, a first- principles DFT code, in the presence of an AC magnetic field, to calculate the response of various configurations of quasi-circular pieces of graphene with or without the presence of substitutional foreign atoms. In order to be able to extend our calculations to larger systems, of the order of tens of thousands of atoms, we used the NRL-TB method, in which the TB matrix elements were fitted so as to reproduce the energy levels of our DFT approach. Results for the energy levels, some selected eigenfunctions, and the current distribution for several configurations will be presented and evaluated vis-a-vis the intended use as almost lossless magnetic resonators.