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arXiv · 1502.01127

Klein tunneling and supercollimation of pseudospin-1 electromagnetic waves

A. Fang·Z. Q. Zhang·Steven G. Louie·C. T. Chan
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Abstract

Pseudospin plays a central role in many novel physical properties of graphene and other artificial systems which have pseudospins of 1/2. Here we show that in certain photonic crystals (PCs) exhibiting conical dispersions at k = 0, the eigenmodes near the "Dirac-like point" can be described by an effective spin-orbit Hamiltonian with a pseudospin of 1, treating wave propagations in the upper cone, the lower cone and a flat band (corresponding to zero refractive index) within a unified framework. The 3-component spinor gives rise to boundary conditions distinct from those of pseudospin-1/2, leading to new wave transport behaviors as manifested in Klein tunneling and supercollimation. For example, collimation can be realized more easily with pseudospin-1 than pseudospin-1/2. The special wave scattering properties of pseudospin-1 photons, coupled with the discovery that the effective photonic "potential" can be varied by a simple change of length scale, may offer new ways to control photon transport.

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A. Fang, Z. Q. Zhang, Steven G. Louie, C. T. Chan. 2016-01-21. Klein tunneling and supercollimation of pseudospin-1 electromagnetic waves. https://doi.org/10.1103/physrevb.93.035422

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