2021 Catalyst: Strategic NZ - DLR Joint research program

Our team Associate Prof Jevon Longdell (Otago), Prof Janik Wolters (DLR), and Dr Christoph Marquardt (MPL) and Harald have been awarded together with funding from the Catalyst: Strategic – New Zealand-DLR Joint Research Programme December 2020. $75,000 go towards studying Long term quantum memories in satellite quantum communications networks


Our Public Summary:

In a world where large scale quantum computation is practical, currently used cryptographic approaches will no longer be secure. A global quantum communication network provides a solution.

This project will investigate the technologies required for long lived quantum memories to be integrated into future satellite quantum communication networks.

A quantum communications network’s key function is the distribution of quantum entanglement between it’s nodes. This allows secure communication between the nodes without having to trust any part of the network. The distributed entanglement will also improve ultraprecise measurements such as global networks of atomic clocks and VLBI (very long baseline interferometry) telescopes. The need for such a quantum network is made more immediate by cheap data storage – caching encrypted data means that the quantum computers of tomorrow will be able to decode the sensitive communications of today.

The simplest way to distribute entanglement is to generate entangled photon pairs and steer them to the desired end points. However loss in the communication channel or intermittent links require the use of quantum repeaters which have at their heart quantum memories. Rare earth quantum memories with record breaking six hour storage times have been demonstrated. Very large bandwidths have been demonstrated and being solid state they have the potential for very high capacity. However in order to be of use for satellite based networks, compatible sources of entanglement and signal routing will be required. We will develop a roadmap for these technologies. This will leverage world leading expertise: from NZ comes expertise in rare-earth quantum memories and nonlinear processes in optical whispering gallery mode resonators, from Germany expertise in satellite quantum communication and entanglement sources.

As a result of the project, satellite quantum communication networks will be one step closer and industry in both countries will be well placed to contribute.

Harald G. L. Schwefel
Associate Professor

I work on Resonat Optics.