Enhanced Quantum Dot Sources and Optical Atomic Memories for Telecommunication InterConnectivity

The EQSOTIC project will develop the components for a telecommunication compatible quantum network. In particular, it will deliver deterministic single- and entangled-pair photon light sources from semiconductor quantum dots, and interface these with atomic-ensemble-based quantum optical memories, all operating near the low-loss C-band wavelength. These are the crucial components for building the future quantum internet.

The EQSOTIC quantum dot sources, are based on indium gallium arsenide – InGaAs. Our approach is to design cavities that enhance emission rates and deliver the purest single photon wavepackets that are matched in bandwidth to the quantum memory.  These devices will also be embedded within a diode structure so that electric fields can both tune the wavelength and stabilize the electronic environment to mitigate decoherence.

The EQSOTIC quantum memories will utilise the off-resonant cascaded absorption protocol – ORCA – in hot rubidium vapour. The memory efficiency will be increased by optimizing the control signal amplitude and phase, and noise will be reduced by new optical pumping schemes. Longer storage times will be achieved by novel dipole rephasing schemes, along with mapping spin-waves to longer lived storage states.

With these optimised devices, EQSOTIC will perform entanglement distribution protocols in a deployed optical fiber network. To facilitate this, EQSOTIC aims to exploit our developed technologies to market, with a focus on creating transportable, compact and rack-based devices. This will enable our source and memory components to be placed within a metropolitan optical fiber network for demonstrating light-matter entanglement between a photon deployed in the fibre network and one retrieved from a quantum memory. EQSOTIC therefore will demonstrate a key building block for a quantum repeater.


  • Coordinator: Patrick Ledingham (University of Southampton, UK)
  • Ian Walmsley (Imperial College London, UK)
  • Peter Michler (University of Stuttgart, DE)
  • Ludwig Arne (Ruhr-Universität Bochum, DE)
  • Niels Gregersen (Technical University of Denmark, DK)
  • Patrick Bowen Montague (NKT Photonics, DK)

Call year

Call 2023

Call topic

Applied Quantum Science

Area of research

Quantum communication

Start date

June 2024


36 months

Funding support

€ 1 667 662

Project status

In Progress