双stub介观环结构中的电子输运特征

采用量子波导理论研究了双stub介观环结构中电子输运特性。结果表明电子透射系数随stub的长度和环的大小而周期地振动,对环的周长和stub的长度做适当的调整,能使电子输运达到100%。并且比较了单stub介观环结构和双stub介观环结构对电子输运的影响,发现双stub的介观环结构对电子输运调制要比单stub介观环结构好。理论研究不仅对基础物理而且对量子器件研究均有重要意义。

Transport Properties of the Electron in One-dimensional Double Stub Mesoscopic Structures

During the last two decades, the development of fabrication technique have made available structures whose dimensions are much smaller than the characteristic length such as the 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. So it is an important question for discussing the transport properties of the electron in mesoscopic structures and it is physics gist to construct quantum devices. Up to now there have been lots of investigations about the mesoscopic system by using varieties theories and experimental methods. But the transport properties of the electron in one-dimensional double stub mesoscopic structures have not been studied. We discuss the transmission properties of electron in double stub mesoscopic structures with quantum waveguide theory. For the sake of simplicity we consider a coherent, dissipationless, quasi-one-dimensional system, and neglect scattering at the junction. We found that the transmission coefficient of electron in one- dimensional double stub mesoscopic structures oscillates with changing the length of the stub and the length of the ring. The transmission coefficient of the electron can be modulated up to 100% by modulating length of the stub and the length of the ring and it is very interesting to notice that the transmission coefficient of the electron modulated by two stubs is better than that modulated by one stub. The theory study is maybe valuable for the study of quantum devices.