Electronic transport for armchair graphene nanoribbons with a potential barrier

This paper studies the electronic transport property through a square potential barrier in armchair-edge graphene nanoribbon (AGNR). Using the Dirac equation with the continuity condition for wave functions at the interfaces between regions with and without a barrier, we calculate the mode-dependent transmission probability for both semiconducting and metallic AGNRs, respectively. It is shown that, by some numerical examples, the transmission probability is generally an oscillating function of the height and range of the barrier for both types of AGNRs. The main difference between the two types of systems is that the magnitude of oscillation for the semiconducting AGNR is larger than that for the metallic one. This fact implies that the electronic transport property for AGNRs depends sensitively on their widths and edge details due to the Dirac nature of fermions in the system.     

太赫兹电磁场照射下量子线中的纳米电子力

研究两端连接电子库的量子线在太赫兹(THz)电磁场横向辐射下的电子力学问题. 在自由电子近似下求得了弹道区二能级电子波函数解析表达式,发现电子概率在两个能态间随线轴坐标作Rabi振荡, 其幅度与外场强度和频率有关. 利用热力学统计算符方法并利用波函数计算出了传导电子对量子线中张力贡献的大小. 其计算结果可表示成与外场无关和与外场有关的两部分之和,前者与已有的实验观测和理论计算结果一致, 而与外场参量有关的部分可用量子相干理论解释. 关键词： 量子线 THz电磁场 纳米电子力     

无反射势阱的Schrdinger方程的精确解

将无反射势阱的Schrdinger方程作自变量双曲函数变换,可使其转化为associated-Legendre方程。从而得到分别用associated-Legendre多项式和函数表示的束缚态和散射态本征函数,并讨论了散射态的归一化和这种精确本征函数的应用问题。本文给出的解较文献中已有的渐近解或特殊值的解具有一般性。     

地下水源热泵系统换热器匹配性研究

建立了地下水源热泵系统实验装置,针对夏季工况和冬季工况分别研究了换热器面积的匹配对系统性能的影响。实验结果分析表明,适当增大冷凝器面积既可提高机组性能,又可避免在冬季工况时冷凝压力过高,保证机组稳定可靠的运行。