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A First-Principles Method for Open Electronic Systems

Xiao Zheng·Fan Wang·GuanHua Chen
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Abstract

We prove that the electron density function of a real physical system can be uniquely determined by its values on any finite subsystem. This establishes the existence of a rigorous density-functional theory for any open electronic system. By introducing a new density functional for dissipative interactions between the reduced system and its environment, we subsequently develop a time-dependent density-functional theory which depends in principle only on the electron density of the reduced system. In the steady-state limit, the conventional first-principles nonequilibrium Green's function formulation for the current is recovered. A practical scheme is proposed for the new density functional: the wide-band limit approximation, which is applied to simulate the transient current through a model molecular device.

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Xiao Zheng, Fan Wang, GuanHua Chen. 2006-06-20. A First-Principles Method for Open Electronic Systems. https://arxiv.org/abs/quant-ph/0606169

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