Fig. 1: Excitation of polaritons in Bi2Se3 by electron beams.
From: Interaction of edge exciton polaritons with engineered defects in the hyperbolic material Bi2Se3
a During the inelastic interaction of fast electrons with the specimen, both surface polaritons and edge polaritons are excited, and consequently the electrons experience energy-losses. The electron energy-loss spectrum is then acquired by the energy-dispersive detection system. b z-component of the electric field associated with edge polatitons propagating along the edges of a Bi2Se3 large cube, at the energy of 4 eV. The edge modes are hybridized in thin films to form symmetric and antisymmetric modes. Here, \(E_1 = 4.3\;{\mathrm{eV}}\), and \(E_2 = 3.8\;{\mathrm{eV}}\), and the thickness of the film is 60 nm. Red and blue colors represent positive and negative values, respectively. c The interaction of hyperbolic edge polaritons at corners and with precisely engineered scatterers of different topology causes reflection, transmission, and radiation of partial waves. d SEM images of the investigated structures. The HEEPs at the upper and lower edge of the nanoplatelets hybridize into a symmetric and an anti-symmetric mode, very similar to surface polaritons in thin films.
