Stochastic Variational Approach to Small Atoms and Molecules Coupled to Quantum Field Modes

TL;DR

This paper introduces a stochastic variational method to calculate energies and wave functions of small atoms and molecules interacting with quantum fields, revealing significant effects of light-matter coupling on electronic states.

Contribution

The work develops a stochastic variational approach for coupled light-matter systems, enabling efficient optimization of wave functions and photon spaces in cavity QED scenarios.

Findings

Light-matter coupling significantly alters electronic states.

The method successfully applied to atoms and molecules like He and H2.

Demonstrates the impact of quantum field modes on small systems.

Abstract

In this work, we present a stochastic variational calculation (SVM) of energies and wave functions of few particle systems coupled to quantum fields in cavity QED. The light-matter coupled system is described by the Pauli-Fierz Hamiltonian. The spatial wave function and the photon spaces are optimized by a random selection process. Examples for a two-dimensional trion and confined electrons as well as for the He atom and the Hydrogen molecule are presented showing that the light-matter coupling drastically changes the electronic states.