Many-body effects between unbosonized excitons

TL;DR

This paper introduces a new many-body theory for composite excitons emphasizing the importance of treating them as non-bosonic particles to accurately capture their interactions, especially in optical nonlinearities.

Contribution

The paper presents a novel many-body theory for composite excitons that avoids bosonization, revealing potential inaccuracies in traditional bosonic Hamiltonian approaches.

Findings

Bosonization can miss significant interaction terms.

Effective bosonic Hamiltonians may omit dominant effects.

Non-bosonized treatment improves accuracy in optical nonlinearity analysis.

Abstract

We here give a brief survey of our new many-body theory for composite excitons, as well as some of the results we have already obtained using it. In view of them, we conclude that, in order to fully trust the results one finds, interacting excitons should not be bosonized: Indeed, all effective bosonic Hamiltonians (even the hermitian ones !) can miss terms as large as the ones they generate; they can even miss the dominant term, as in problems dealing with optical nonlinearities.