%0 Journal Article
%A Roslyak, Oleksiy
%A Gumbs, Godfrey
%A Huang, Danhong
%T Graphene nanoribbons in criss-crossed electric and magnetic fields
%D 2010
%R 10.1098/rsta.2010.0215
%J Philosophical Transactions of the Royal Society A: Mathematical,
Physical and Engineering Sciences
%P 5431-5443
%V 368
%N 1932
%X Graphene nanoribbons (GNRs) in mutually perpendicular electric and magnetic fields are shown to exhibit dramatic changes in their band structure and electron-transport properties. A strong electric field across the ribbon induces multiple chiral Dirac points, closing the semiconducting gap in armchair GNRs. A perpendicular magnetic field induces partially formed Landau levels as well as dispersive surface-bound states. Each of the applied fields on its own preserves the even symmetry Ek=E−k of the sub-band dispersion. When applied together, they reverse the dispersion parity to be odd, which gives Ee,k=−Eh,−k, and mix the electron and hole sub-bands within the energy range corresponding to the change in potential across the ribbon. This leads to oscillations of the ballistic conductance within this energy range. The broken time-reversal symmetry provides dichroism in the absorption of the circularly polarized light. As a consequence, one can observe electrically enhanced Faraday rotation, since the edges of the ribbon provide formation of the substantial density of states.
%U http://rsta.royalsocietypublishing.org/content/roypta/368/1932/5431.full.pdf