石墨烯介观环中的持续电流理论研究

发布时间：2018-04-23 22:20

本文选题：M?bius介观环 + 石墨烯介观环　；参考：《华南理工大学》2015年硕士论文

【摘要】：在紧束缚近似下,研究了简单纳米管、M?bius介观环和石墨烯介观环中的电子态和持续电流问题。(1)解析推导了简单纳米管和M?bius介观环的电子态和持续电流。M?bius介观环中电子的能量本征值本征态依赖于横向通道数的奇偶性。研究发现,简单纳米管和M?bius介观环产生的持续电流随磁通的变化具有类似的变化关系,对于持续电流的研究得到了一些新的现象和结果。当横向通道数与环周长满足某特定关系时,持续电流随磁通的变化呈线性或趋于正弦关系变化。(2)解析求解了扶手椅型边界石墨烯介观环和锯齿型边界石墨烯介观环的能量本征值问题,计算和讨论了不同大小尺寸的介观环中持续电流随Aharonov-Bohm(A-B)磁通的变化。研究表明,对于扶手椅型石墨烯介观环持续电流显著地依赖于介观环的几何结构;零能量附近的能级可以承载较大的持续电流,而远离零能量的其它能级对持续电流的贡献很小。分析研究了锯齿型边界石墨烯介观环的两种电子态即驻波态和边缘态;不同大小尺寸的介观环中的持续电流随Aharonov-Bohm(A-B)磁通的变化以及系统的边缘态所产生的电流情况。研究表明,锯齿型边界石墨烯介观环系统产生的持续电流随磁通呈正弦关系变化。
[Abstract]:In the tight bound approximation, The electron states and persistent currents in the mesoscopic rings of simple nanotubes Mnbius and graphene were studied. The energy eigenvalues of electrons in simple nanotubes and M?bius mesoscopic rings were derived. The eigenstates depend on the parity of the number of transverse channels. It is found that the continuous current produced by simple nanotubes and M?bius mesoscopic rings has a similar relationship with magnetic flux. Some new phenomena and results have been obtained for the study of persistent current. When the number of transverse channels satisfies a particular relationship with the circumference of the ring, The energy eigenvalues of the armchair boundary graphene mesoscopic ring and the sawtooth boundary graphene mesoscopic ring are solved analytically. The variation of the sustained current with the Aharonov-Bohmm A-B) flux in mesoscopic rings of different sizes has been calculated and discussed. The results show that the sustained current of the armchair graphene mesoscopic ring is significantly dependent on the geometric structure of the mesoscopic ring, and the energy level near zero energy can carry a large sustained current. Other energy levels far away from zero energy contribute little to the sustained current. The two electronic states of the zigzag boundary graphene mesoscopic ring, the standing wave state and the edge state, the variation of the sustained current with the Aharonov-BohmmA-B) flux in the mesoscopic ring with different sizes and the current generated by the edge state of the system are studied. The results show that the continuous current generated by the zigzag boundary graphene mesoscopic ring system is sinusoidal with the flux.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ127.11

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