Electrically tunable g-factors in quantum dot molecular spin states

TL;DR

This study demonstrates how electric fields can tune the g-factors of spin states in quantum dot molecules, revealing resonant behaviors linked to molecular wavefunction distributions.

Contribution

It introduces a phenomenological model explaining g-factor tuning via wavefunction amplitude changes in coupled quantum dots under electric fields.

Findings

G-factors can be strongly tuned by electric fields in quantum dot molecules.

Resonant changes in g-factors are linked to bonding and antibonding orbital formation.

The proposed model explains the wavefunction-dependent g-factor modulation.

Abstract

We present a magneto-photoluminescence study of individual vertically stacked InAs/GaAs quantum dot pairs separated by thin tunnel barriers. As an applied electric field tunes the relative energies of the two dots, we observe a strong resonant increase or decrease in the g-factors of different spin states that have molecular wavefunctions distributed over both quantum dots. We propose a phenomenological model for the change in g-factor based on resonant changes in the amplitude of the wavefunction in the barrier due to the formation of bonding and antibonding orbitals.