title: Time-dependent density functional theory for open systems with a positivity-preserving decomposition scheme for environment spectral functions.
abstract: Understanding electronic dynamics on material surfaces is fundamentally important for applications including nanoelectronics, inhomogeneous catalysis, and photovoltaics. Practical approaches based on time-dependent density functional theory for open systems have been developed to characterize the dissipative dynamics of electrons in bulk materials. The accuracy and reliability of such approaches depend critically on how the electronic structure and memory effects of surrounding material environment are accounted for. In this work, we develop a novel squared-Lorentzian decomposition scheme, which preserves the positive semi-definiteness of the environment spectral matrix. The resulting electronic dynamics is guaranteed to be both accurate and convergent even in the long-time limit. The long-time stability of electronic dynamics simulation is thus greatly improved within the current decomposition scheme. The validity and usefulness of our new approach are exemplified via two prototypical model systems: quasi-one-dimensional atomic chains and two-dimensional bilayer graphene.
authors: Beijing Computational Science Research Center, No. 3 He-Qing Road, Beijing 100084, China.
authors: RuLin
authors: R
authors: Wang
authors: Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors: Xiao
authors: X
authors: Zheng
authors: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: YanHo
authors: Y
authors: Kwok
authors: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: Hang
authors: H
authors: Xie
authors: Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
authors: GuanHua
authors: G
authors: Chen
authors: Beijing Computational Science Research Center, No. 3 He-Qing Road, Beijing 100084, China.
authors: ChiYung
authors: C
authors: Yam