Probing exciton/exciton interactions with entangled photons: theory

TL;DR

This paper presents a theoretical model demonstrating how entangled photon scattering from a molecular dimer can reveal exciton interactions, providing a new method to probe many-body correlations in materials.

Contribution

It introduces a diagrammatic scattering theory linking photon entanglement properties to exciton interactions in molecular systems.

Findings

Photon entanglement can be generated via coupled qubit interactions.

The von Neumann entropy of outgoing photons correlates with exciton exchange and repulsion.

The model suggests experimental setups for probing many-body correlations.

Abstract

Quantum entangled photons provide a sensitive probe of many-body interactions and offer an unique experimental portal for quantifying many-body correlations in a material system. In this paper, we present a theoretical demonstration of how photon-photon entanglement can be generated via interactions between coupled qubits. Here we develop a model for the scattering of an entangled pair of photons from a molecular dimer. We develop a diagrammatic theory for the scattering matrix and show that one can correlate the von Neumann entropy of the outgoing bi-photon wave function to exciton exchange and repulsion interactions. We conclude by discussing possible experimental scenarios for realizing these ideas.