ar X iv : q ua nt - p h / 06 06 16 9 v 1 2 0 Ju n 20 06 A First - Principles Method for Open Electronic Systems
نویسنده
چکیده
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 timedependent 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.
منابع مشابه
ar X iv : q ua nt - p h / 06 06 17 6 v 1 2 1 Ju n 20 06 On quantum positive dynamical maps
The new arguments indicating that non-completely positive maps can describe open quantum evolution are given. This work was partially supported by KBN grant PB/1490/PO3/2003/25 and SCALA (IST-2004-015714) 1
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