Three-particle electron-hole complexes in two-dimensional electron systems

TL;DR

This paper investigates three-particle electron-hole complexes in a quantum Hall insulator, revealing new excited states, their photoluminescence signatures, and their interactions with plasma oscillations and plasmarons.

Contribution

It provides theoretical predictions and experimental observations of excited trion states and their interactions in two-dimensional electron systems under magnetic fields.

Findings

Observation of new photoluminescence lines from excited trion states

Identification of plasmaron formation involving three-particle complexes

Confirmation of theoretical trion energy spectrum predictions

Abstract

Three-particle complexes consisting of two holes in the completely filled zero electron Landau level and an excited electron in the unoccupied first Landau level are investigated in a quantum Hall insulator. The distinctive features of these three-particle complexes are an electron-hole mass symmetry and the small energy gap of the quantum Hall insulator itself. Theoretical calculations of the trion energy spectrum in a quantizing magnetic field predict that, besides the ground state, trions feature a hierarchy of excited bound states. In agreement with the theoretical simulations, we observe new photoluminescence lines related to the excited trion states. A relatively small energy gap allows the binding of three-particle complexes with magnetoplasma oscillations and formation of plasmarons. The plasmaron properties are investigated experimentally.