当前位置: 澳门新普京下载 >> 学术动态 >> 正文

张淳报告:Steady-State Density Functional Theory: From Fundamental to

作者 : 张淳 教授 发布于 : 2015/09/18

报告题目:Steady-State Density Functional Theory: From Fundamental to

Molecular Electronics

 

报告人:张淳 教授(新加坡国立大学物理系)

 

联系人:陈克求 教授

 

时间:2015-9-22 上午10-11.30

地点:物理楼307

 

报告内容:

 

We present a steady-state density functional theory (SS-DFT) for modeling electronic and transport properties of nonequilibrium quantum systems such as molecular junctions under a finite bias. Based on nonequilibrium quantum statistics, we show that given two electron densities, the total electron density (ρt) and the density of current-carrying electrons (ρn), the steady-state properties of a nonequilibrium quantum system can be uniquely determined. A direct consequence of the theory is that the ground-state density functional theory (GS-DFT) based approach is in principle not correct for steady-state nonequilibrium systems. A dual mean-field (DMF) approach that is applicable to realistic quantum systems is then derived. The key idea of the DMF approach is that the current-carrying electrons ‘feel’ a different mean-field potential from equilibrium electrons that do not contribute to electric current. The SS-DFT and DMF approach have been applied to various kinds of molecular scale junctions. Electronic structures and I-V characteristics from SS-DFT are compared with those obtained from the conventional GS-DFT based transport approach. If time permitting, we will also discuss one example to show how SS-DFT can be used to explain puzzling experimental observations.

 

报告人简历:Dr. Chun Zhang earned his PhD in physics from University of Florida in 2004. After 3 years of postdoc research experiences in Georgia Institute of Technology, he took a faculty job in National University of Singapore (NUS). He now is associate professor in Department of Physics and also Chemistry at NUS. Dr. Zhang's research is mainly focused on theoretical/computational modelling of materials at various scales ranging from small molecules to bulk systems. His current interests include molecular electronics/spintronics and surface physics/chemistry. In total, Dr. Zhang has published 60+ papers with 2610+ citations.

XML 地图 | Sitemap 地图