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

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 a 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 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.