We introduce a novel optical interface between a singlet-triplet spin qubit and a photonic qubit which would offer new prospects for future quantum communication applications. The interface is based on a 220 nm thick GaAs/Al-GaAs heterostructure membrane and features a gate-defined singlet-triplet qubit, a gate-defined optically active quantum dot, a photonic crystal cavity and a bot-tom gold reflector. All essential components can be lithographically defined and deterministically fabricated, which greatly increases the scalability of on-chip in-tegration. According to our FDTD simulations, the interface provides an overall coupling efficiency of 28.7% into a free space Gaussian beam, assuming an SiO2 interlayer filling the space between the reflector and the membrane. The performance can be further increased to 48.5% by undercutting this SiO2 interlayer below the photonic crystal.
@article{arxiv.2406.14392,
title = {An efficient singlet-triplet spin qubit to fiber interface assisted by a photonic crystal cavity},
author = {Kui Wu and Sebastian Kindel and Thomas Descamps and Tobias Hangleiter and Jan Christoph Müller and Rebecca Rodrigo and Florian Merget and Hendrik Bluhm and Jeremy Witzens},
journal= {arXiv preprint arXiv:2406.14392},
year = {2024}
}