Extended dissipaton theory with application to adatom-graphene composite

TL;DR

This paper introduces an extended dissipaton theory that accurately models complex environmental interactions in strongly correlated electronic systems, demonstrated through spectral analysis of an adatom on graphene.

Contribution

The paper develops an extended dissipaton framework that handles non-Markovian, non-perturbative environmental couplings, including quadratic interactions, which was not previously available.

Findings

Spectral functions of adatoms on graphene show unique features due to graphene's band structure.

The extended theory accurately captures environmental effects in strongly correlated systems.

Comparison with metal environments highlights the influence of substrate properties.

Abstract

In this paper, we present the extended dissipaton theory, including the dissipaton-equation-of-motion formalism and the equivalent dissipaton-embedded quantum master equation. These are exact, non-Markovian, and non-perturbative theories, capable of handling not only linear but also quadratic environmental couplings. These scenarios are prevalent in a variety of strongly correlated electronic systems, including mesoscopic nanodevices and superconductors. As a demonstration, we apply the present theory to simulate the spectral functions of an adatom on a graphene substrate. We analyze the spectral peaks in the presence of the graphene substrate and compare them to those obtained in conventional metal environments. The adatom's spectral functions reveal intricate behaviors arising from the band structure of graphene.