We investigate the spin-coherence decay of NV−-spins interacting with the strongly-coupled bath of nitrogen defects in diamond layers. For thin diamond layers, we demonstrate that the spin-coherence times exceed those of bulk diamond, thus allowing to surpass the limit imposed by high defect concentrations in bulk. We show that the stretched-exponential parameter for the short-time spin-coherence decay is governed by the hyperfine interaction in the bath, thereby constraining random-noise models. We introduce a novel method based on the cluster-correlation expansion applied to strongly-interacting bath partitions. Our results facilitate material development for quantum-technology devices.
@article{arxiv.2401.16169,
title = {Spin coherence in strongly coupled spin baths in quasi-two-dimensional layers},
author = {Philip Schätzle and Reyhaneh Ghassemizadeh and Daniel F. Urban and Thomas Wellens and Peter Knittel and Florentin Reiter and Jan Jeske and Walter Hahn},
journal= {arXiv preprint arXiv:2401.16169},
year = {2025}
}