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arXiv · 1404.1170

Valley-antisymmetric potential in graphene under dynamical deformation

Ken-ichi Sasaki·Yasuhiro Tokura·Hideki Gotoh
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Abstract

When graphene is deformed in a dynamical manner, a time-dependent potential is induced for the electrons. The potential is antisymmetric with respect to valleys, and some straightforward applications are found for Raman spectroscopy. We show that a valley-antisymmetric potential broadens Raman $D$ band but does not affect $2D$ band, which is already observed by recent experiments. The space derivative of the valley antisymmetric potential gives a force field that accelerates intervalley phonons, while it corresponds to the longitudinal component of the previously discussed pseudoelectric field acting on the electrons. Effects of a pseudoelectric field on the electron is quite difficult to observe due to the valley-antisymmetric coupling constant, on the other hand, such obstacle is absent for intervalley phonons with $A_{1g}$ symmetry that constitute the $D$ and $2D$ bands.

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Ken-ichi Sasaki, Yasuhiro Tokura, Hideki Gotoh. 2014-07-17. Valley-antisymmetric potential in graphene under dynamical deformation. https://doi.org/10.1103/physrevb.90.205402

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