# Non-Adiabatic Dynamics in Single-Electron Tunneling Devices with Time-Dependent Density Functional Theory

## TL;DR

This paper develops a time-nonlocal exchange-correlation potential within time-dependent density functional theory to simulate non-adiabatic electron dynamics in single-electron tunneling devices, revealing the role of dynamical potential steps.

## Contribution

It introduces a novel time-nonlocal exchange-correlation potential for simulating non-adiabatic dynamics in quantum dot systems within TDDFT.

## Key findings

- Identification of a dynamical potential step linked to electron relaxation times
- Explicit connection between time evolution of the potential step and physical relaxation processes
- Discussion on extending simulations to larger mesoscopic systems

## Abstract

We simulate the dynamics of a single-electron source, modeled as a quantum dot with on-site Coulomb interaction and tunnel coupling to an adjacent lead, in time-dependent density functional theory. Based on this system, we develop a time-nonlocal exchange-correlation potential by exploiting analogies with quantum-transport theory. The time non-locality manifests itself in a dynamical potential step. We explicitly link the time evolution of the dynamical step to physical relaxation time scales of the electron dynamics. Finally, we discuss prospects for simulations of larger mesoscopic systems.