Tunable cavity coupling of a single SnV$^{-}$ center in nanodiamond across bad-emitter and bad-cavity regimes

TL;DR

This paper demonstrates tunable coupling of a single SnV$^{-}$ center in nanodiamond to a microcavity, showing a transition from bad-emitter to bad-cavity regimes and potential for quantum network applications.

Contribution

It introduces controlled coupling of a single SnV$^{-}$ center to a tunable cavity, highlighting regime transitions and cavity-enhanced emission at cryogenic temperatures.

Findings

Achieved controlled coupling of a single SnV$^{-}$ center to a tunable cavity.

Observed transition from bad-emitter to bad-cavity regime.

Measured Purcell factor exceeding 1.7 at 4 K.

Abstract

Efficient coupling between quantum emitters and optical cavities is essential for scalable quantum photonic technologies. Group IV vacancy centers in diamond, particularly the negatively charged tin-vacancy center, have emerged as promising candidates due to their spectral stability, high Debye-Waller factor and large orbital splitting in ground-states. Here, we demonstrate controlled couplinag of a single negatively charged tin vacancy center hosted in a nanodiamond to a fully tunable Fabry-Perot microcavity. At cryogenic temperatures, we access the weak coupling regime and observe a transition from the bad-emitter to the bad-cavity regime as the optical transition of the color center narrows. At 4 K, a Purcell factor exceeding 1.7 is measured, confirming cavity-enhanced emission. The obtained results demonstrate the potential of SnV$^{-}$ centers in nanodiamonds as a coherent single-photon source for quantum networks.