Excited conduction electrons, conduction holes, and valence holes in monolayer electron-doped graphene exhibit unusual Coulomb decay rates. The deexcitation processes are studied using the screened exchange energy. They might utilize the intraband and interband single-particle excitations, as well as the plasmon modes, depending on the quasiparticle states and the Fermi energies. The low-lying valence holes can decay through the undamped acoustic plasmon, so that they present very fast Coulomb deexcitations, nonmonotonous energy dependence, and anisotropic behavior. However, the low-energy conduction electrons and holes are similar to those in a two-dimensional electron gas. The higher-energy conduction states and the deeper-energy valence ones behave similarly in the available deexcitation channels and have a similar dependence of decay rate on the wave vector.

中文翻译：

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单层掺杂石墨烯的库仑衰减率


单层电子掺杂石墨烯中激发的传导电子、传导空穴和价空穴表现出不寻常的库仑衰减率。使用筛选的交换能量研究去激励过程。他们可能会利用带内和带间单粒子激发以及等离子体激元模式，具体取决于准粒子态和费米能量。低位价空穴可以通过无阻尼的声等离子激元衰减，因此它们呈现非常快的库仑去激发、非单调的能量依赖性和各向异性行为。然而，低能传导电子和空穴与二维电子气中的类似。高能传导态和深能价态在可用的去激励通道中表现相似，并且衰减率对波矢量具有相似的依赖性。