臺灣博碩士論文加值系統

本篇論文利用緊束模型(tight-binding model)來探討零維有限尺度石墨帶系統的電子性質。我們計算了能帶、態密度、能隙、簡併度及電子的波函數等物理量。並討論它們在幾何結構、寬度和長度、懸空鍵的有無以及外加磁場等因素影響下的變化。我們發現零維石墨帶的性質主要是由懸空鍵所決定。而在外加磁場作用下，零維石墨帶的電子能帶結構存在二種磁通量的對稱性：Φ→ -Φ，Φ→1-Φ，而Φ→Φ+phi0 可由前兩個推導得到。 是基本磁通量(phi0 =hc/e )。

In this paper, Tight-binding model is used to study the electronic
properties of finite sized nanographite ribbons. We calculate energy
band , density of state, energy gap, degeneracy,and wavefunction and
also discuss their variation under the effect of several factors geometrical
structure,width&lenth , dangling bond ,via magnetic field. We found that
physical properties of finite sized nanographite ribbons are mainly
determined by the dangling bond. Under the effect of magnetic field ,
there are two kind symmetries : Φ→ -Φ, Φ→1-Φ and the third kind
symmetry : Φ→Φ+ phi0 can be derived from the former two. is the basic unit of magnetic flux.

目 錄
第一章導論…………………………………………………...1
第二章石墨帶的理論模型…………………………………...8
2-1 無外加磁場效應的緊束模型…………………………...8
2-2 外加磁場效應下的緊束模型…………………………. .9
第三章結果與討論………………………………………….12
3-1 能帶.......................................................................12
3-2 電子波函數……………………………….…...14
3-3 能隙…………………………………………….. 22
3-4 態密度………………………………………………….27
3-5 磁電子性質………………………………………34
第四章 結論…………………………………………………44
參考文獻………………………………………………………….45

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