Abstract
本篇論文探討兩個與石墨相關系統的多體效應：石墨衍生物 (graphite intercalation compounds) 與石墨同軸微管(graphene tubules)。這兩個系統都是由石墨層形成，而且可以藉由填塞原子或分子 增加自由載子的密度。基於此，我們可以根據單層石墨的能帶結構來探討 二者的基本性質。由於不同的幾何結構，這兩個系統表現出迴異的物理性 質。石墨衍生物是層狀石墨週期性的堆疊而成，可以兼具一維，二維，與 三維的物理性質。我們探討了它的雜質屏蔽和剩餘電阻，自能修正，與激 子效應。石墨同軸微管是由石墨層捲成的圓柱結構體系，而它表現出一維 與二維的物理性質。我們探討了石墨微管的基本激發，磁電漿子和永續電 流，與自能修正。論文裡，我們特別著重多粒子理論與實驗之間的關聯， 並且預測了一些尚待實驗証實的特性。研究的結果顯示，多粒子效應是理 解這兩個系統基本性質所必須探討的。 In this thesis, we studied many-body effects in two graphite- related systems: graphite intercalation compounds (GIC's) and graphene tubules. Both of the systems are made of graphite sheets, and atoms or moleculars could be intercalated into them to enhance the carrier density but without modifying the honey comb structure of the graphite layers. Owing to these similarities, we could build up our theory for the systems by employing the unique band structure of a single graphite sheet. Very different symmetries of the two structures, however, make them behave differently. GIC's are made of periodically staked graphite layers; as a result, the system could exhibit rich one-, two-, and three-dimensional properties. For GIC's, we have studied their screening behaviors, transport properties, self-energy correction, and excitonic effects. A graphene tubule is a rolled-up graphite sheet in a cylindrical form with a diameter in the nanometers. Due to the microscopic structure, graphene tubules have novel one- and two-dimensional physical properties. In this work, we studied elementary excitations, magnetoplasmons and persistent currents, and self-energy correction of the graphene tubules. During the studies, we have paid special attention to compare the many-body theory with the experiments, and have predicted some novel features which have yet to be verified experimentally. The results of this research clearly illustrate that the many-body effects are fundamental to the understanding of the important physical properties of these two systems.