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arXiv · 1711.06429

Double refraction and spin splitter in a normal-hexagonal semiconductor junction

Peng Lv·Ning Dai·Qing-Feng Sun
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Abstract

In analogy with light refraction at optical boundary, ballistic electrons also undergo refraction when propagate across a semiconductor junction. Establishing a negative refractive index in conventional optical materials is difficult, but the realization of negative refraction in electronic system is conceptually straightforward, which has been verified in graphene p-n junctions in recent experiments. Here, we propose a model to realize double refraction and double focusing of electric current by a normal-hexagonal semiconductor junction. The double refraction can be either positive or negative, depending on the junction being n-n type or p-n type. Based on the valley-dependent negative refraction, a spin splitter (valley splitter) is designed at the p-n junction system, where the spin-up and spin-down electrons are focused at different regions. These findings may be useful for the engineering of double lenses in electronic system and have underlying application of spin splitter in spintronics.

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Peng Lv, Ning Dai, Qing-Feng Sun. 2017-11-17. Double refraction and spin splitter in a normal-hexagonal semiconductor junction. https://doi.org/10.1103/physrevb.97.235425

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