论文标题
电石墨烯中对声子极化的电气控制
Electrical Control over Phonon Polarization in Strained Graphene
论文作者
论文摘要
我们探索了通过磁通谐振的单轴线损伤石墨烯中声子极化的可调性。单轴菌株将LO的变性和声子提升，产生了两个交叉线性极化的声子模式和拉曼G峰的分裂。我们利用石墨烯中的强电子偶联以及与磁音 - phonon共振的非谐振耦合，以诱导栅极可调的圆形圆音子二色症。这与应变诱导的G峰分裂，使我们能够将两个线性极化的G模式声子调整为圆形的声子模式。我们能够通过静电场达到纯粹的40％的圆形声子极化，并可以通过从电子到孔掺杂来调整其符号。这为声子的角动量提供了前所未有的静电控制，这为通向语音应用铺平了道路。
We explore the tunability of the phonon polarization in suspended uniaxially strained graphene by magneto-phonon resonances. The uniaxial strain lifts the degeneracy of the LO and TO phonons, yielding two cross-linearly polarized phonon modes and a splitting of the Raman G peak. We utilize the strong electron-phonon coupling in graphene and the off-resonant coupling to a magneto-phonon resonance to induce a gate-tunable circular phonon dichroism. This, together with the strain-induced splitting of the G peak, allows us to controllably tune the two linearly polarized G mode phonons into circular phonon modes. We are able to achieve a circular phonon polarization of up to 40 % purely by electrostatic fields and can reverse its sign by tuning from electron to hole doping. This provides unprecedented electrostatic control over the angular momentum of phonons, which paves the way toward phononic applications.
