石墨烯带中不同形状量子点电导的研究

A Study on Conductance of the Zigzag Grapheme Strip with the Quantum Dot of Different Shape

通过采用紧束缚模型,描述锯齿形石墨烯结构中电导的数值计算方法。研究长为L、宽为W的无掺杂的锯齿形石墨烯条形带中几种不同形状的量子点的电导对静电偏压的依赖关系,发现对于圆形的量子点的电导,随着偏压区域的面积比例减小,出现尖锐的共振峰,并且把这种情况与束缚态的出现相联系,而对于其它结构的量子点,其电导对于偏压的关系也做了一些讨论。

By using tight-binding model we describe a method for the numerical calculations of the conductance in zigzag grapheme structures.With the method we calculate the conductance of several different shape regions that subject to an electrostatic bias voltage in an ideal strip of zigzag grapheme（length L,width W,no impurities of defects）.We find sharp resonances that narrow upon reducing the area of the gated region for the quantum dot of the circular shape and relate this case to the existence of confined electronic states.In view of the quantum dots of other shapes,the relation between the conductance and the bias voltage is discussed and the conductance is independent on the gate voltage.