Time-dependent quantum transport: A practical scheme using density functional theory
We present a computationally tractable scheme of time-dependent transport phenomena within open-boundary time-dependent density functional theory. Within this approach all the response properties of a system are determined from the time propagation of the set of >occupied> Kohn-Sham orbitals u...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2005 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:dnet:digitalcsic_::e2939da91b8fdf83e4387b64e9028372 |
| Acceso en línea: | http://hdl.handle.net/10261/98014 |
| Access Level: | acceso abierto |
| Sumario: | We present a computationally tractable scheme of time-dependent transport phenomena within open-boundary time-dependent density functional theory. Within this approach all the response properties of a system are determined from the time propagation of the set of >occupied> Kohn-Sham orbitals under the influence of the external bias. This central idea is combined with an open-boundary description of the geometry of the system that is divided into three regions: left right leads and the device region (>real simulation region>). We have derived a general scheme to extract the set of initial states in the device region that will be propagated in time with proper transparent boundary-condition at the device lead interface. This is possible due to a new modified Crank-Nicholson algorithm that allows an efficient time-propagation of open quantum systems. We illustrate the method in one-dimensional model systems as a first step towards a full first-principles implementation. In particular we show how a stationary current develops in the system independent of the transient-current history upon application of the bias. The present work is ideally suited to study ac transport and photon-induced charge-injection. Although the implementation has been done assuming clamped ions, we discuss how it can be extended to include dissipation due to electron-phonon coupling through the combined simulation of the electron-ion dynamics as well as electron-electron correlations. © 2005 The American Physical Society. |
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