This title appears in the Scientific Report :
2017
Please use the identifier:
http://dx.doi.org/10.1103/PhysRevE.95.033309 in citations.
Please use the identifier: http://hdl.handle.net/2128/14029 in citations.
Self-energy matrices for electron transport calculations within the real-space finite-difference formalism
Self-energy matrices for electron transport calculations within the real-space finite-difference formalism
The self-energy term used in transport calculations, which describes the coupling between electrode and transition regions, is able to be evaluated only from a limited number of the propagating and evanescent waves of a bulk electrode. This obviously contributes toward the reduction of the computati...
Saved in:
Personal Name(s): | Tsukamoto, Shigeru (Corresponding author) |
---|---|
Ono, Tomoya / Hirose, Kikuji / Blügel, Stefan | |
Contributing Institute: |
Quanten-Theorie der Materialien; IAS-1 JARA - HPC; JARA-HPC JARA-FIT; JARA-FIT Quanten-Theorie der Materialien; PGI-1 |
Published in: | Physical Review E Physical review / E, 95 95 (2017 2017) 3 3, S. 033309 033309 |
Imprint: |
Woodbury, NY
Inst.
2017
2017-03-20 2017-03-01 |
DOI: |
10.1103/PhysRevE.95.033309 |
Document Type: |
Journal Article |
Research Program: |
Controlling Configuration-Based Phenomena Controlling Spin-Based Phenomena |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/14029 in citations.
The self-energy term used in transport calculations, which describes the coupling between electrode and transition regions, is able to be evaluated only from a limited number of the propagating and evanescent waves of a bulk electrode. This obviously contributes toward the reduction of the computational expenses in transport calculations. In this paper, we present a mathematical formula for reducing the computational expenses further without using any approximation and without losing accuracy. So far, the self-energy term has been handled as a matrix with the same dimension as the Hamiltonian submatrix representing the interaction between an electrode and a transition region. In this work, through the singular-value decomposition of the submatrix, the self-energy matrix is handled as a smaller matrix, whose dimension is the rank number of the Hamiltonian submatrix. This procedure is practical in the case of using the pseudopotentials in a separable form, and the computational expenses for determining the self-energy matrix are reduced by 90% when employing a code based on the real-space finite-difference formalism and projector-augmented wave method. In addition, this technique is applicable to the transport calculations using atomic or localized basis sets. Adopting the self-energy matrices obtained from this procedure, we present the calculation of the electron transport properties of C20 molecular junctions. The application demonstrates that the electron transmissions are sensitive to the orientation of the molecule with respect to the electrode surface. In addition, channel decomposition of the scattering wave functions reveals that some unoccupied C20 molecular orbitals mainly contribute to the electron conduction through the molecular junction. |