Efficient method for the calculation of ballistic quantum transport

We present an efficient method to calculate the ballistic transmission function and current of an arbitrarily shaped, multiterminal two- or three-dimensional open device. It is shown that the calculation of the energy dependent transmission function can be reduced to a single calculation of some stationary states of the isolated device and the inversion of a small matrix that is energy dependent. The size of this matrix is shown to be governed by the size of the boundary region between the leads and the device. The method that we term contact block reduction method is illustrated by a numerical example. (C) 2003 American Institute of Physics.