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arXiv · 1710.05281

Coulomb scattering rates of excited states in germanene

Po-Hsin Shih·Chih-Wei Chiu·Jhao-Ying Wu·Thi-Nga Do·Ming-Fa Lin
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Abstract

The excited conduction electrons, conduction holes and valence holes in monolayer germanene exhibit the feature-rich Coulomb decay rates. The dexcitation processes are studied using the Matsubara's screened exchange energy. They might utilize the intraband single-particle excitations (SPEs), the interband SPEs, and three kinds of plasmon modes, depending on the quasiparticle states and the Fermi energies. The low-lying valence holes can decay by the undamped acoustic plasmon, so that they present very fast Coulomb deexcitations, the non-monotonous energy dependence and the anisotropic behavior. However, the low-energy conduction holes and electrons behave as 2D electron gas. The high-energy conduction states and the deep-energy valence ones are similar in the available deexcitation channels and the dependence of decay rate on wave vector k.

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Po-Hsin Shih, Chih-Wei Chiu, Jhao-Ying Wu, Thi-Nga Do, Ming-Fa Lin. 2017-10-15. Coulomb scattering rates of excited states in germanene. https://doi.org/10.1103/physrevb.97.195302

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