论文标题
当前有偏见的Dirac节点的等离激元增益
Plasmonic gain in current biased tilted Dirac nodes
论文作者
论文摘要
表面等离子体可极端限制光，遭受高内在电子损失的影响。已经表明，刺激的电子发射可以将能量转移到等离子体上并补偿高内在损失。迄今为止，这些实现依赖于引入与表面等离子体的外部增益介质。在这里，我们提出，当沿流离失所的电子孔口袋施加电流偏置时，没有需要外部增益介质的电流偏置时，将具有近距离电子和孔费米口袋的二维材料中的等离子体体验到增益。作为一个典型的例子，我们认为从1T $'$ -MX $ _2 $材料的家族中考虑了$ _2 $，其电子结构可以在类型的II倾斜大型迪拉克模型中描述。我们发现，在MA $ $ M $ $^{ - 1} $的订单上，非本地等离子响应经历了实验可访问的电流的显着增益。此外，从等音曲线发现的等离子体的基团速度表明，放大的等离子沿垂直于Dirac节点倾斜的方向高度准直时，当沿其施加电流时。
Surface plasmons, which allow extreme confinement of light, suffer from high intrinsic electronic losses. It has been shown that stimulated emission of electrons can transfer energy to plasmons and compensate for the high intrinsic losses. To-date, these realizations have relied on introducing an external gain media coupled to the surface plasmon. Here, we propose that plasmons in two-dimensional materials with closely located electron and hole Fermi pockets can experience gain, when an electrical current bias is applied along the displaced electron-hole pockets, without the need for an external gain media. As a prototypical example, we consider WTe$_2$ from the family of 1T$'$-MX$_2$ materials, whose electronic structure can be described within a type-II tilted massive Dirac model. We find that the nonlocal plasmonic response experiences prominent gain for experimentally accessible currents on the order of mA$μ$m$^{-1}$. Furthermore, the group velocity of the plasmon found from the isofrequency curves imply that the amplified plasmons are highly collimated along a direction perpendicular to the Dirac node tilt when the electrical current is applied along it.
