Direct photonic coupling of a semiconductor quantum dot and a trapped ion

TL;DR

This paper demonstrates the first direct photonic coupling between a semiconductor quantum dot and a trapped ion, showing controllable state changes via single photons, advancing hybrid quantum network development.

Contribution

It introduces a novel experimental setup achieving direct photonic coupling between a quantum dot and a trapped ion, overcoming linewidth mismatch with cavity enhancement.

Findings

Single photons from a quantum dot can change the state of a trapped ion.

High-finesse cavity improves coupling efficiency.

Classical correlations enable information transfer between systems.

Abstract

Coupling individual quantum systems lies at the heart of building scalable quantum networks. Here, we report the first direct photonic coupling between a semiconductor quantum dot and a trapped ion and we demonstrate that single photons generated by a quantum dot controllably change the internal state of an $\textrm{Yb}^+$ ion. We ameliorate the effect of the sixty-fold mismatch of the radiative linewidths with coherent photon generation and a high-finesse fiber-based optical cavity enhancing the coupling between the single photon and the ion. The transfer of information presented here via the classical correlations between the $\sigma_z$-projection of the quantum-dot spin and the internal state of the ion provides a promising step towards quantum state-transfer in a hybrid photonic network.