用量子力学格林函数法解决电导问题的探索

Green function method of quantum mechanics to solve the problem of exploration conductance

格林函数的优点是可以用它推导出输运系数的准确表达式,并在各种条件下作近似计算.但是在很多的实际问题中,如一些较复杂的有限尺寸量子系统,要推导其格林函数的解析表达式是一件很困难的事,因此必须要通过数值计算来解决.方法是首先把系统分离成很多格点,然后通过计算这些格点及格点间的格林函数,进而得出整个体系的格林函数的一种有效数值方法.

The Green function shows great advantages in deduction of the accurate expression of transport coefficient and approximate calculation in various conditions.But in many practical problems,such as in some quantum systems which have more complex and limited size,it is very difficult to deduce the analytical expressions of the Green′s function,so numerical calculation must be used.The method is to separate the system into many lattice points,and then to get an effective numerical method of the whole system through calculating the lattice points of the Green′s function.