Monday, February 25, 2013

1302.5533 (Yury Bliokh et al.)

Charge transport in graphene and light propagation in periodic
dielectric structures with metamaterials: a comparative study
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Yury Bliokh, Valentin Freilikher, Franco Nori
We explore the optical properties of periodic layered media containing left-handed metamaterials. This study is facilitated by several analogies between the propagation of light in such media and charge transport in graphene. We derive conditions when these two problems become equivalent, i.e., the equations and the boundary conditions for the corresponding wave functions coincide. It is shown that the photonic band-gap structure of a periodic system built of alternating left- and right-handed dielectrics contains conical singularities similar to the Dirac points in the energy spectrum of charged quasiparticles in graphene. Such singularities in the zone structure of the infinite systems give rise to rather unusual properties of the light transport in finite samples. In a single numerical experiment (propagation of a Gaussian beam through a mixed stack of normal and meta-dielectrics) we demonstrate simultaneously four Dirac point-induced anomalies: (i) diffusion-like decay of the intensity at forbidden frequencies; (ii) focusing and defocussing of the beam; (iii) absence of the transverse shift of the beam; (iv) a spatial analog of the Zitterbewegung effect. All these phenomena take place in media with non-zero average refractive index, and can be tuned by changing the geometrical and electromagnetic parameters of the sample.
View original: http://arxiv.org/abs/1302.5533

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