标题： 有偏置电流的石墨烯中等离子体增益和非互易性的方向依赖性 显示英文标题

标题： Directional dependence of the plasmonic gain and nonreciprocity in drift-current biased graphene

摘要： 在这里，我们使用石墨烯电导率的伽利略型和相对论型多普勒频移变换，研究漂移电流偏置下表面等离子体的非互易传播和放大。 与之前的研究一致，两种电导率模型都由于漂移电子引起的拖曳效应，预测了表面等离子体的强非互易传播。 特别是，伽利略多普勒频移模型在等离子体色散中导致更强的光谱不对称性，并具有单向传播的区域。 值得注意的是，当漂移电流偏置的石墨烯片与等离子体基底（即SiC）耦合时，两种电导率模型都预测了宽广平面方向角度范围内的非互易等离子体放大区域，其中相对论多普勒频移模型的等离子体放大率显著更高。 显示英文摘要

摘要： Here, we investigate the nonreciprocal propagation and amplification of surface plasmons in drift-current biased graphene, using both Galilean and relativistic-type Doppler shift transformations of the graphene's conductivity. Consistent with previous studies, both conductivity models predict strongly nonreciprocal propagation of surface plasmons due to the drag effect caused by the drifting electrons. In particular, the Galilean Doppler shift model leads to stronger spectral asymmetries in the plasmon dispersion with regimes of unidirectional propagation. Remarkably, it is shown that both conductivity models predict regimes of nonreciprocal plasmon amplification in a wide angular sector of in-plane directions when the drift-current biased graphene sheet is coupled to a plasmonic substrate (namely, SiC), with the plasmon amplification rate being substantially higher for the relativistic Doppler shift model.