Wang, Y. and Yam, C. -Y. and Frauenheim, Th. and Chen, G. H. and Niehaus, T. A. (2011) An efficient method for quantum transport simulations in the time domain. CHEMICAL PHYSICS, 391 (1). pp. 69-77. ISSN 0301-0104, 1873-4421
Full text not available from this repository. (Request a copy)Abstract
An approximate method based on adiabatic time dependent density functional theory (TDDFT) is presented, that allows for the description of the electron dynamics in nanoscale junctions under arbitrary time dependent external potentials. The density matrix of the device region is propagated according to the Liouville-von Neumann equation. The semi-infinite leads give rise to dissipative terms in the equation of motion which are calculated from first principles in the wide band limit. In contrast to earlier ab initio implementations of this formalism, the Hamiltonian is here approximated in the spirit of the density functional based tight-binding (DFTB) method. Results are presented for two prototypical molecular devices and compared to full TDDFT calculations. The temporal profile of the current traces is qualitatively well captured by the DFTB scheme. Steady state currents show considerable variations, both in comparison of approximate and full TDDFT, but also among TDDFT calculations with different basis sets. (C) 2011 Published by Elsevier B. V.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | DENSITY-FUNCTIONAL THEORY; TIGHT-BINDING; COMPLEX MATERIALS; STATE; Time dependent density functional theory; Quantum transport; Molecular electronics; DFTB |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Alumni or Retired Professors > Group Thomas Niehaus |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 26 May 2020 13:54 |
| Last Modified: | 26 May 2020 13:54 |
| URI: | https://pred.uni-regensburg.de/id/eprint/19784 |
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