
%0 Journal Article
%A Zhang, C. 
%T Electromagnetic Absorption in Two-dimensional Systems under a Magnetic Field and a Unidirectional Periodic Potential
%J Australian Journal of Physics
%D 2000/02/02
%V 53
%N 1
%P 65-76
%K 
%R https://doi.org/10.1071/PH99024
%U https://www.publish.csiro.au/paper/PH99024 
%X The absorption of electromagnetic waves by a high mobility two-dimensional electron gas subjected to a magnetic field and a weak periodic potential is investigated. We show that the periodic modulation on the Laudau states has a profound effect on the absorption of electromagnetic waves. We develop a formalism which treats the electron&#8211;electron interaction beyond the random-phase-approximation (RPA) and includes the electron-impurity scattering in the lowest order. A RPA dielectric function was employed to study the electromagnetic absorption in modulated systems. Simultaneous excitation of an electron&#8211;hole pair with finite momentum contributes significantly to the absorption around and below the cyclotron frequency. Such a process is absent for a uniform electron gas under a magnetic field. 
