Infrared Topological Plasmons in Graphene

We propose a two-dimensional plasmonic platform—periodically patterned monolayer graphene—which hosts topological one-way edge states operable up to infrared frequencies. We classify the band topology of this plasmonic system under time-reversal-symmetry breaking induced by a static magnetic field. At finite doping, the system supports topologically nontrivial band gaps with mid-gap frequencies up to tens of terahertz. By the bulk-edge correspondence, these band gaps host topologically protected one-way edge plasmons, which are immune to backscattering from structural defects and subject only to intrinsic material and radiation loss. Our findings reveal a promising approach to engineer topologically robust chiral plasmonic devices and demonstrate a realistic example of high-frequency topological edge states.Received 23 February 2017Publisher error corrected 20 June 2017DOI:https://doi.org/10.1103/PhysRevLett.118.245301© 2017 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPlasmonsQuantum fluids & solidsTopological phases of matterCondensed Matter, Materials & Applied Physics