Improved recursive Green's function formalism for quasi one-dimensional systems with realistic defects

JOURNAL OF COMPUTATIONAL PHYSICS

卷:334

Article

Teichert, Fabian^1,3,4  Zienert, Andreas²  Schuster, Jorg^3,4  Schreiber, Michael^1,4 

[1] Tech Univ Chemnitz, Fac Nat Sci, Inst Phys, D-09126 Chemnitz, Germany

[2] Tech Univ Chemnitz, Ctr Microtechnol, D-09126 Chemnitz, Germany

[3] Fraunhofer Inst Elect Nano Syst ENAS, D-09126 Chemnitz, Germany

[4] Tech Univ Dresden, Dresden Ctr Computat Mat Sci DCMS, D-01062 Dresden, Germany

关键词: Recursive Green's function formalism (RGF);    Renormalization decimation algorithm;    (RDA);    Electronic transport;    Carbon nanotube (CNT);    Defect;   

DOI  :  10.1016/j.jcp.2017.01.024

来源: Elsevier

【 摘 要 】

We derive an improved version of the recursive Green's function formalism (RGF), which is a standard tool in the quantum transport theory. We consider the case of disordered quasi one-dimensional materials where the disorder is applied in form of randomly distributed realistic defects, leading to partly periodic Hamiltonian matrices. The algorithm accelerates the common RGF in the recursive decimation scheme, using the iteration steps of the renormalization decimation algorithm. This leads to a smaller effective system, which is treated using the common forward iteration scheme. The computational complexity scales linearly with the number of defects, instead of linearly with the total system length for the conventional approach. We show that the scaling of the calculation time of the Green's function depends on the defect density of a random test system. Furthermore, we discuss the calculation time and the memory requirement of the whole transport formalism applied to defective carbon nanotubes. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

Free