Plexcitons: Dirac points and topological modes

Publication Type:



arXiv [cond-mat.mes-hall] (2015)






Plexcitons are polaritonic modes that result from the strong coupling between excitons and plasmons. We consider plexcitons emerging from the
interaction of excitons in an organic molecular layer with surface
plasmons in a metallic film. We predict the emergence of Dirac cones in
the two-dimensional bandstructure of plexcitons due to the inherent
alignment of the excitonic transitions in the organic layer. These Dirac
cones may open up in energy by simultaneously interfacing the metal with a
magneto-optical layer and subjecting the whole system to a perpendicular
magnetic field. The resulting energy gap becomes populated with
topologically protected one-way modes which travel at the interface of
this plexcitonic system. Our theoretical proposal suggests that plexcitons
are a convenient and simple platform for the exploration of exotic phases
of matter as well as of novel ways to direct energy flow at the nanoscale.