Department of Physics, National Cheng Kung University, Tainan, Taiwan 701.
ACS Nano. 2011 Feb 22;5(2):1026-32. doi: 10.1021/nn1024847. Epub 2011 Jan 4.
In this paper, we calculated the dielectric function, the loss function, the magnetoplasmon dispersion relation and the temperature-induced transitions for graphene in a uniform perpendicular magnetic field B. The calculations were performed using the Peierls tight-binding model to obtain the energy band structure and the random-phase approximation to determine the collective plasma excitation spectrum. The single-particle and collective excitations have been precisely identified based on the resonant peaks in the loss function. The critical wave vector at which plasmon damping takes place is clearly established. This critical wave vector depends on the magnetic field strength as well as the levels between which the transition takes place. The temperature effects were also investigated. At finite temperature, there are plasma resonances induced by the Fermi distribution function. Whether such plasmons exist is mainly determined by the field strength, temperature, and momentum. The inelastic light scattering spectroscopies could be used to verify the magnetic field and temperature induced plasmons.
在本文中，我们计算了在均匀垂直磁场 B 中石墨烯的介电函数、损耗函数、磁等离子体色散关系和温度诱导的转变。计算使用 Peierls 紧束缚模型来获得能带结构，并使用随机相位近似来确定集体等离子体激发谱。基于损耗函数中的共振峰，精确地识别了单粒子和集体激发。明确确定了发生等离子体阻尼的临界波矢。该临界波矢不仅取决于磁场强度，还取决于跃迁发生的能级。还研究了温度效应。在有限温度下，费米分布函数会引起等离子体共振。是否存在这样的等离子体主要取决于场强、温度和动量。非弹性光散射光谱可用于验证磁场和温度诱导的等离子体。
