Time-dependent density-functional theory for real-time electronic dynamics on material surfaces

TL;DR

This paper extends time-dependent density-functional theory (TDDFT) to open systems, enabling accurate real-time simulations of electronic dynamics on material surfaces, crucial for understanding surface phenomena and electron transfer processes.

Contribution

The authors develop an open-system TDDFT framework that accurately models real-time electronic responses on material surfaces, overcoming limitations of conventional TDDFT for isolated or periodic systems.

Findings

Successfully simulated electron relaxation on graphene surface.

Modeled electron transfer across molecule-graphene interface.

Validated transient and long-time electron dynamics.

Abstract

The real-time electronic dynamics on material surfaces is critically important to a variety of applications. However, their simulations have remained challenging for conventional methods such as the time-dependent density-functional theory (TDDFT) for isolated and periodic systems. By extending the applicability of TDDFT to systems with open boundaries, we achieve accurate atomistic simulations of real-time electronic response to local perturbations on material surfaces. Two prototypical scenarios are exemplified: the relaxation of an excess electron on graphene surface, and the electron transfer across the molecule-graphene interface. Both the transient and long-time asymptotic dynamics are validated, which accentuates the fundamental importance and unique usefulness of an open-system TDDFT approach. The simulations also provide insights into the characteristic features of temporal electron evolution and dissipation on surfaces of bulk materials.