磁场对含杂质的介观结构中持续电流的影响  

Effect of Magnetic Field on Persistent Currents in Mesoscopic Structure with an Impurity

作　　者：霍淑芬[1] 肖景林[1] 

机构地区：[1]河北科技师范学院数理系

出　　处：《发光学报》2008年第2期225-228,共4页Chinese Journal of Luminescence

基　　金：国家自然科学基金资助项目(10347002,10747002)

摘　　要：采用量子波导理论,研究了含杂质的介观结构中电子的透射几率和持续电流。结果表明:电子的透射几率及持续电流均随磁通量的变化作周期性振荡,周期大小是1;无论是否存在杂质,反共振(T=0)均出现在f=0.5的位置(当0≤f<1)。当两电子库间电流发生反转时,双Aharonov-Bohm环各环中的持续电流的大小均发生明显改变。Recent developments of fabrication techniques have made available structure whose dimensions are much smaller than the characteristic length, such as mean free path and phase-coherence length of an electron. These structures are referred to as mesoscopic system. The physical properties of the mesoscopic system are strongly affected by quantum-interference effects, and one of the interesting phenomena is the persistent current in a ring threaded by magnetic flux. The purpose of this paper is to reveal the behavior of the persistent currents of mesoscopic structure with an impurity by the quantum waveguide theory. It is found that both the transmission coefficient of electron and persistent currents oscillate periodically with changing of magnetic flux with a period off= 1. In the region of 0≤f〈 1, the antiresonance occurs atf=0. 5. When the flowing direction of the current reverses, the amplitude of persistent current in each ring of the double Aharonov-Bohm rings changes.

关 键 词：量子波导理论 介观结构 δ-函数杂质 持续电流 

分 类 号：O469[理学—凝聚态物理] O472.4[理学—电子物理学]