Hierarchical quantum master equation approach to vibronic reaction dynamics at metal surfaces

TL;DR

This paper introduces a hierarchical quantum master equation method for accurately simulating vibronic reaction dynamics at metal surfaces, capturing nonadiabatic effects and electronic friction in a nonperturbative manner.

Contribution

It presents a new numerically exact quantum dynamical approach combining hierarchical equations with discrete nuclear representations for surface reactions.

Findings

Method accurately models desorption and bond rupture processes.

Captures nonadiabatic and electronic friction effects.

Demonstrates versatility across different surface reaction models.

Abstract

A novel quantum dynamical method to simulate vibronic reaction dynamics in molecules at metal surfaces is proposed. The method is based on the hierarchical quantum master equation approach and uses a discrete variable representation of the nuclear degrees of freedom in combination with complex absorbing potentials and an auxiliary source term. It provides numerically exact results for a range of models. By taking the coupling to the continuum of electronic states of the surface properly into account, nonadiabatic processes can be described and the effect of electronic friction is included in a nonperturbative and non-Markovian way. Illustrative application to models for desorption of a molecule at a surface and current-induced bond rupture in single-molecule junctions demonstrate the performance and versatility of the method.