Direct observation of metastable hot trions in an individual quantum dot

TL;DR

This study directly observes metastable hot trions in a single quantum dot, revealing their spin structure, excited states, and magnetic properties through advanced spectroscopy techniques.

Contribution

It introduces a method to stabilize and directly observe hot trions in a quantum dot, providing detailed insights into their excited state spectrum and spin configurations.

Findings

Metastable hot trions exhibit strong optical activity.

Excited singlet and triplet states are mapped and characterized.

Magneto-optical measurements reveal g-factors and diamagnetic responses.

Abstract

Magneto photoluminescence and excitation spectroscopy are used to probe the excited state spectrum of negatively charged trions in a InGaAs quantum dot. A single dot optical charging device allows us to selectively prepare specific few (1e, 2e) electron states and stabilize hot trions against decay via electron tunnelling from excited orbital states. The spin structure of the excited state results in the formation of metastable trions with strong optical activity that are directly observed in luminescence. Excitation spectroscopy is employed to map the excited singlet and triplet states of the two electron wavefunction and fine structure splittings are measured for the lowest lying and excited orbital states. Magneto-optical measurements allow us to compare the g-factors and diamagnetic response of different trion states.