Single spin defects in 2D transition-metal dichalcogenides are natural spin-photon interfaces for quantum applications. Here we report high-field magneto-photoluminescence spectroscopy from three emission lines (Q1, Q2 and Q*) of He-ion induced sulfur vacancies in monolayer MoS2. Analysis of the asymmetric PL lineshapes in combination with the diamagnetic shift of Q1 and Q2 yields a consistent picture of localized emitters with a wavefunction extent of ∼ 3.5 nm. The distinct valley-Zeeman splitting in out-of-plane B-fields and the brightening of dark states through in-plane B-fields necessitates spin-valley selectivity of the defect states and lifted spin-degeneracy at zero field. Comparing our results to ab-initio calculations identifies the nature of Q1 and Q2 and suggests that Q* is the emission from a chemically functionalized defect. Analysis of the optical degree of circular polarization reveals that the Fermi level is a parameter that enables the tunability of the emitter. These results show that defects in 2D semiconductors may be utilized for quantum technologies.
@article{arxiv.2205.10286,
title = {Spin-defect characteristics of single sulfur vacancies in monolayer $\text{MoS}_2$},
author = {Alexander Hötger and Tomer Amit and Julian Klein and Katja Barthelmi and Thomas Pelini and Alex Delhomme and Sergio Rey and Marek Potemski and Clément Faugeras and Galit Cohen and Daniel Hernangómez-Pérez and Takashi Taniguchi and Kenji Watanabe and Christoph Kastl and Jonathan J. Finley and Sivan Refaely-Abramson and Alexander W. Holleitner and Andreas V. Stier},
journal= {arXiv preprint arXiv:2205.10286},
year = {2024}
}