Combining density functional theory with macroscopic QED for quantum light-matter interactions in 2D materials

• Published in: Nature communications Vol. 12; no. 1; pp. 2778 - 13
• Main Authors: Svendsen, Mark Kamper, Kurman, Yaniv, Schmidt, Peter, Koppens, Frank, Kaminer, Ido, Thygesen, Kristian S.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.05.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/119/995; 639/925/918/1054; Approximation; Computer applications; Conductors; Density functional theory; Dipoles; Electron states; First principles; Graphene; Heterostructures; Humanities and Social Sciences; Intersubband transitions; Mathematical analysis; multidisciplinary; Nanostructured materials; Quantum electrodynamics; Quantum wells; Science; Science (multidisciplinary); Transition metal compounds; Two dimensional materials; Wave functions
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-23012-3

A quantitative and predictive theory of quantum light-matter interactions in ultra thin materials involves several fundamental challenges. Any realistic model must simultaneously account for the ultra-confined plasmonic modes and their quantization in the presence of losses, while describing the electronic states from first principles. Herein we develop such a framework by combining density functional theory (DFT) with macroscopic quantum electrodynamics, which we use to show Purcell enhancements reaching 10 7 for intersubband transitions in few-layer transition metal dichalcogenides sandwiched between graphene and a perfect conductor. The general validity of our methodology allows us to put several common approximation paradigms to quantitative test, namely the dipole-approximation, the use of 1D quantum well model wave functions, and the Fermi’s Golden rule. The analysis shows that the choice of wave functions is of particular importance. Our work lays the foundation for practical ab initio-based quantum treatments of light-matter interactions in realistic nanostructured materials. The development of a quantitative and predictive theory of quantum light-matter interactions in ultrathin materials is both a conceptual and computational challenge. Here, the authors develop such a framework by combining density functional theory with macroscopic quantum electrodynamics, and use it to quantify the Purcell effect in van der Waals heterostructures.