# Independent electrical control of two quantum dots coupled through a photonic-crystal waveguide

## TL;DR

This paper demonstrates independent electrical control of two quantum dots coupled via a photonic-crystal waveguide, enabling scalable multi-emitter quantum photonic systems with coherent interactions.

## Contribution

It introduces a method to individually tune and probe two quantum dots in a waveguide, advancing solid-state quantum emitter integration.

## Key findings

- Successful individual electrical tuning of two quantum dots.
- Observation of coherent coupling signatures between emitters.
- Ability to perform spectroscopy on one emitter using the other.

## Abstract

Efficient light-matter interaction at the single-photon level is of fundamental importance in emerging photonic quantum technology. A fundamental challenge is addressing multiple quantum emitters at once, as intrinsic inhomogeneities of solid-state platforms require individual tuning of each emitter. We present the realization of two semiconductor quantum dot emitters that are efficiently coupled to a photonic-crystal waveguide and individually controllable by applying a local electric Stark field. We present resonant transmission and fluorescence spectra in order to probe the coupling of the two emitters to the waveguide. We exploit the single-photon stream from one quantum dot to perform spectroscopy on the second quantum dot positioned 16$\mu$m away in the waveguide. Furthermore, power-dependent resonant transmission measurements reveals signatures of coherent coupling between the emitters. Our work provides a scalable route to realizing multi-emitter collective coupling, which has inherently been missing for solid-state deterministic photon emitters.