First-principles investigation of transient current in molecular devices by using complex absorbing potentials

2013/02/06 by Lei Zhang, L. Zhang, J. Chen +3 · 43 citations
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #Benchmark (surveying) #Computational physics #Computer science #Density functional theory #Formalism (music) #Molecular Junctions and Nanostructures #Non-equilibrium thermodynamics #Physics #Quantum mechanics #Semiconductor materials and devices #Statistical physics #Transient (computer programming) #cond-mat.mes-hall

paper · pdf · doi:10.1103/physrevb.87.205401

published in Physical Review B 87(20) (American Physical Society)

arxiv created 2013/02/06 · openalex publication_date 2013/05/01 · arxiv updated 2015/06/12 · openalex created_date 2019/07/30 · openalex updated_date 2026/08/05

Abstract

Based on the nonequilibrium Green's function (NEGF) coupled with density function theory (DFT), namely, NEGF-DFT quantum transport theory, we propose an efficient formalism to calculate the transient current of molecular devices under a step-like pulse from first principles. By combining NEGF-DFT with the complex absorbing potential (CAP), the computational complexity of our formalism (NEGF-DFT-CAP) is proportional to O(N) where N is the number of time steps in the time-dependent transient current calculation. Compared with the state-of-the-art algorithm of first-principles time-dependent calculation that scales with at least N², this order N technique drastically reduces the computational burden making it possible to tackle realistic molecular devices. We have presented a detailed discussion on how to implement this scheme numerically from first principles. To check the accuracy of our method, we carry out the benchmark calculation compared with NEGF-DFT formalism and they agree well with each other. As an application of this method, we investigate the transient current of a molecular device Al--C₃--Al from first principles.

Citations

• Time-dependent transport in interacting and non-interacting mesoscopic systems
• Determination of complex absorbing potentials from the electron self-energy
• Transient regime in nonlinear transport through many-level quantum dots
• Inelastic Scattering and Local Heating in Atomic Gold Wires
• ab initio modeling of open systems: charge transfer, electron conduction, and molecular switching of a C₆₀ device
• Time-dependent quantum transport: A practical scheme using density functional theory
• Transient dynamics of molecular devices under a steplike pulse bias
• Time-dependent transport through a mesoscopic structure
• Time-dependent density-functional theory for open systems