Quantum Electrodynamics Coupled-Cluster Theory: Exploring Photon-Induced Electron Correlations

TL;DR

This paper introduces a quantum electrodynamics coupled-cluster method (QED-CCSD) that models electron-photon interactions within quantum systems, utilizing advanced tensor algebra for high-performance computing.

Contribution

The work extends traditional CCSD to include photon-induced electron correlations, integrating bosonic degrees of freedom into a scalable computational framework.

Findings

Demonstrates how photon interactions modify electronic ground states.

Provides a scalable implementation suitable for modern computing platforms.

Validates the method with numerical benchmarks.

Abstract

We present our successful implementation of the quantum electrodynamics coupled-cluster method with single and double excitations (QED-CCSD) for electronic and bosonic amplitudes, covering both individual and mixed excitation processes within the ExaChem program package, which relies on the Tensor Algebra for Many-body Methods (TAMM) infrastructure. TAMM is a parallel heterogeneous tensor library designed for utilizing modern computing platforms, from laptops to leadership-class computing resources. This developed computational framework extends the traditional CCSD method to incorporate the intricate interplay between electronic and bosonic degrees of freedom, providing a comprehensive description of quantum phenomena. We discuss theoretical foundations, algorithmic details, and numerical benchmarks to demonstrate how the integration of bosonic degrees of freedom alters the electronic ground state. The interactions between electrons and photons within an optical cavity are modeled using the Pauli-Fierz Hamiltonian within the dipole approximation in the length gauge. The integration of QED effects within the CCSD framework contributes to a more accurate and versatile model for simulating complex quantum systems, thereby opening avenues for a better understanding, prediction, and manipulation of various physical phenomena.