不同参数的不对称阶梯型量子阱等离激元特性研究

Plasmon Characteristics of Different Structure Parameter Dependence in AlGaAs/GaAs Asymmetric Step Quantum Wells

用无规相近似的二子带模型,系统研究了阶梯层宽度、深阱宽度、阶梯层的Al组分(阶梯层势垒的高度)对Al Ga As/Ga As不对称阶梯型量子阱中准二维电子气的等离激元特性的影响。发现子带间等离激元模的能量大小取决于基态和第一激发态的能级差,而模的长短取决于这两个能级波函数的交叠大小。这些结论可能为研究空间不对称效应对准二维电子气特性的影响以及基于阶梯型量子阱结构的器件应用等方面提供有益的参考。

We have investigated the different structure parameter dependence of plasmon characteristics in A1GaAs! GaAs asymmetric step quantum wells （ASQWs） within the framework of random-phase approximation in two- subband model. By adjusting the thickness of the step layer, the thickness of the well layer and the AI content of the step layer, we have found that the energy of the intersubband plasmon that depends on the energy difference of the ground state and the first state, while the length of the mode depends on the overlap level of the wavefunctions of the two states. These characteristics can provide useful references for the asymmetric effects on the properties in quasi-two-dimensional system for the application-oriented ASQWs device structures.