Tuning the exciton g-factor in single InAs/InP quantum dots

TL;DR

This study demonstrates how the exciton g-factor in single InAs/InP quantum dots can be tuned by adjusting their height, with experimental data supported by theoretical calculations showing the influence of confinement on hole g-factors.

Contribution

It provides the first experimental demonstration of g-factor tunability in InAs/InP quantum dots via dimensional control using nanotemplates.

Findings

G-factor increases from -2 to +1.2 as dot height decreases

Theoretical calculations match experimental trends

Quantum dot dimensions influence hole orbital angular momentum mixing

Abstract

Photoluminescence data from single, self-assembled InAs/InP quantum dots in magnetic fields up to 7 T are presented. Exciton g-factors are obtained for dots of varying height, corresponding to ground state emission energies ranging from 780 meV to 1100 meV. A monotonic increase of the g-factor from -2 to +1.2 is observed as the dot height decreases. The trend is well reproduced by sp3 tight binding calculations, which show that the hole g-factor is sensitive to confinement effects through orbital angular momentum mixing between the light-hole and heavy-hole valence bands. We demonstrate tunability of the exciton g-factor by manipulating the quantum dot dimensions using pyramidal InP nanotemplates.