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arXiv · 1501.05553

Single-Valley Engineering in Graphene Superlattices

Yafei Ren·Xinzhou Deng·Changsheng Li·Jeil Jung·Changgan Zeng·Zhenyu Zhang·Qian Niu·Zhenhua Qiao
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Abstract

The two inequivalent valleys in graphene preclude the protection against inter-valley scattering offered by an odd-number of Dirac cones characteristic of Z2 topological insulator phases. Here we propose a way to engineer a chiral single-valley metallic phase with quadratic crossover in a honeycomb lattice through tailored \sqrt{3}N *\sqrt{3}N or 3N *3N superlattices. The possibility of tuning valley-polarization via pseudo-Zeeman field and the emergence of Dresselhaus-type valley-orbit coupling are proposed in adatom decorated graphene superlattices. Such valley manipulation mechanisms and metallic phase can also find applications in honeycomb photonic crystals.

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Yafei Ren, Xinzhou Deng, Changsheng Li, Jeil Jung, Changgan Zeng, Zhenyu Zhang, Qian Niu, Zhenhua Qiao. 2015-01-22. Single-Valley Engineering in Graphene Superlattices. https://doi.org/10.1103/physrevb.91.245415

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