Ab initio tight-binding LMTO method for nonequilibrium electron transport in nanosystems

作者：Faleev SV^*; Leonard F; Stewart DA; van Schilfgaarde M

来源：Physical Review B, 2005, 71(19): 195422.

DOI：10.1103/PhysRevB.71.195422

We present an ab initio method for calculation of the electronic structure and electronic transport of nanoscale systems coupled to electrodes with applied voltage bias. The method is based on the local density approximation of density functional theory and implemented in the framework of the tight-binding linear muffin-tin orbital approach in its atomic sphere approximation. A fully atomistic description of the electrodes and the nanosystem is used, and the self-consistent charge and electrostatic potential for the system under applied bias is calculated using the nonequilibrium Green's NEGF) approach. General expressions for the lesser Green's function and transmission coefficient obtained within NEGF theory are rewritten using auxiliary Green's functions that are defined by the inverse of the short-ranged structural constants. This reformulation of the theory with auxiliary Green's functions allows the use of very effective and well-developed tight-binding techniques. The method is applied to three systems: a single benzene di-thiol molecule coupled to (111) gold electrodes, a single gold atom coupled to (100) gold electrodes, and a single platinum atom coupled to (100) platinum electrodes.

• 出版日期2005-5