Strong coupling between quantum dot exciton spin states and a photonic crystal cavity

TL;DR

This study demonstrates magnetic field tuning of quantum dot exciton spin states to achieve strong coupling with a photonic crystal cavity, enabling energy shifts up to 0.83 meV without losing coupling strength.

Contribution

It introduces magnetic field tuning as a method to control quantum dot spin states and their coupling to photonic cavities, enhancing quantum photonic device capabilities.

Findings

Strong coupling observed between quantum dot spin states and cavity.

Magnetic field tuning shifts energy levels by up to 0.83 meV.

Coupling strength remains robust during tuning.

Abstract

We apply magnetic fields of up to 7 T to an indium arsenide (InAs) quantum dot (QD) strongly coupled to a photonic crystal cavity. The field lifts the degeneracy of QD exciton spin states, and tune their emission energy by a combination of diamagnetic and Zeeman energy shifts. We use magnetic field tuning to shift the energies of the two spin states to be selectively on resonance with the cavity. Strong coupling between the cavity and both spin states is observed. Magnetic field tuning enables energy shifts as large as 0.83 meV without significant degradation of the QD-cavity coupling strength.