Quantum Dot based Quantum Network – QDQN

Semiconductor quantum dots are excellent candidates to implement a quantum network with a scalable solid-state technology. Quantum dots generate single photons acting as flying quantum bits and the spin of a trapped carrier acts as a quantum node able to store the quantum information. In the last few years, impressive progress has been made, with the development of spin-photon interfaces, optical gates operating at the very few photon level and the fabrication of ultrabright quantum light sources. Scaling these technologies requires an efficient interface between stationary and flying quantum bits, an interface that the PI team has successfully developed in the last few years, leading to the fabrication of a new generation of fully indistinguishable bright single photon sources that promises scaling optical quantum technologies, and the demonstration of the manipulation of a single quantum bit with few-photon pulses.

In the ERC project, our objective is to demonstrate the scalability of quantum technologies based on quantum dots in microcavities. Our first goal is to reach a whole new level in quantum light generation and manipulation by increasing the entanglement generation and distribution rate by several orders of magnitude with ultrabright single photon sources (WPA). Our second objective is to bring new functionalities to optical quantum technologies by demonstrating deterministic gates and photon cluster state generation using spin in cavities (WPB). Our third goal is to implement elementary quantum networks based on photon exchange between several quantum dot devices, some acting as sources, others as quantum nodes (WPC). Finally, we propose a new approach to couple several solid-state quantum bits, at the frontier of solid-state quantum optics and optomechanics: as we are able to control the phoTonic environment of a single quantum dot, we aim at controlling its phoNonic environment and at developing an acoustic quantum bus to entangle two quantum dots (WPD).

This project was close to the funding limit at the ERC Cog 2016 call. In this ANR Tremplin ERC we will experimentally demonstrate the first building blocks of WPA and WPB+C. Namelly, we will fabricate mutually indistinguishable ultrabright single photon sources and coherently manipulate a single quantum dot spin in a cavity