Comment on ``Two-dimensional charged-biexciton complexes''

TL;DR

This paper critiques previous calculations of charged biexciton complexes in 2D, highlighting that their formation isn't guaranteed by Coulomb interactions alone and suggesting alternative explanations if such complexes are experimentally observed.

Contribution

It challenges prior oversimplified models of charged biexciton complexes, emphasizing the need for more comprehensive mechanisms to explain their binding.

Findings

Charged biexciton complexes may not always form bound states.

Pure Coulomb interaction is insufficient to guarantee binding.

Alternative mechanisms might be necessary to explain experimental observations.

Abstract

We re-examine the results of A. Thilagam [Phys. Rev. B 55, 7804 (1997)], who calculated the ratio of the binding energies of the two dimensional exciton complexes. We point out that, for charged biexciton complexes, this calculation is oversimplified, and these systems do not always form bound states if they interact via pure Coulomb interaction. If experiment proved the existence of these objects, their bindings would have to be explained by other mechanisms.