Influence of the Pauli exclusion principle on scattering properties of cobosons

TL;DR

This paper investigates how the Pauli exclusion principle affects the scattering behavior of composite bosons, like excitons, highlighting the role of entanglement and mode occupation in scattering rates and super-bunching phenomena.

Contribution

It introduces a methodology to analyze the impact of Pauli exclusion on scattering properties of composite bosons, applicable to various systems beyond bi-fermion bosons.

Findings

Scattering rates increase with entanglement between fermionic constituents.

Probabilities of accommodating bosons depend on unoccupied Schmidt modes.

Super-bunching enhances scattering in systems with macroscopically occupied modes.

Abstract

We examine the influence of the Pauli exclusion principle on the scattering properties of composite bosons (cobosons) made of two fermions, such as the exciton quasiparticle. The scattering process incorporates boson-phonon interactions that arise due to lattice vibrations. Composite boson scattering rates increase with the entanglement between the two fermionic constituents, which comes with a larger number of available single-fermion states. An important role is played by probabilities associated with accommodating an incoming boson among the remaining unoccupied Schmidt modes in the initial composite system. While due attention is given to bi-fermion bosons, the methodology is applicable to any composite boson made up of smaller boson fragments. Due to super-bunching in a system of multiple boson condensates such as bi-bosons, there is enhanced scattering associated with bosons occupying macroscopically occupied Schmidt modes, in contrast to the system of bi-fermion pairs.