Non-perturbative Mass Renormalization Effects in Non-relativistic Quantum Electrodynamics

TL;DR

This paper explores how multi-mode photonic environments, such as optical cavities, non-perturbatively affect mass renormalization and properties of quantum matter, with implications for polaritonic chemistry and cavity materials engineering.

Contribution

It demonstrates the importance of non-perturbative mass renormalization in ab initio QED simulations and its impact on ground- and excited-state properties in cavity environments.

Findings

Mass renormalized depends on photonic environment and particle number.

Photon fields enhance particle confinement and modify molecular potential surfaces.

Comparison shows differences from free-space mass-renormalization approximations.

Abstract

In this work we investigate the effects that multi-mode photonic environments, e.g., optical cavities, have on the properties of quantum matter. We highlight the importance of the non-perturbative mass renormalization procedure for ab initio quantum electrodynamics simulations and how it connects to common approximations used in polaritonic chemistry and cavity materials engineering. We focus on one-dimensional systems which can be solved exactly for large number of photon modes. First, we apply mass renormalization to free particles. The value of the renormalized mass depends on the details of the photonic environment and on the number of particles. We then show how the multi-mode photon field influences various ground- and excited-state properties of atomic and molecular systems. For instance, we observe the enhancement of particle confinement in the binding potential for the atomic system, and the modification of the potential energy surfaces of the molecular dimer due to photon-mediated long-range interactions. We also highlight how these changes compare to the common free-space mass-renormalization approximation employed in electronic structure theory and quantum chemistry. Since such phenomena are enhanced under strong light-matter coupling in a cavity environment they will become relevant for the emerging fields of polaritonic chemistry and cavity materials engineering.