Researchers at Heriot-Watt University could revolutionise the future of global quantum communications through the development of ‘satellite to ground receiver’ technology.

The receivers, which use photonic technology, will be designed as compact, lightweight and highly affordable devices that could fuel the commercialization and widespread use of quantum communications.

These technologies, researchers said, could have the potential to open up the use of encrypted quantum comms in space.

Optical Quantum Key Distribution

Optical quantum key distribution, also known as QKD, is now acknowledged as a mature quantum communication protocol. This outlines the process of sharing encrypted data between two parties and has the potential to address a number of data vulnerability issues by using quantum properties of qubits.

A qubit, or a quantum bit, is the quantum computing equivalent to the binary digit – or bit – in classical computing. While a bit is the basic unit of information in classical computing, a qubit is a basic unit of information in a quantum computer.

This could prove highly valuable to organisations or companies sending sensitive data and information, including high-value financial data or government communications.

Limitations

Currently, QKD systems are earth-based and are limited in their range – around a few hundred kilometres – unless expensive detectors, lab-based settings or specialist fibres are used.

This has proven to be an inefficient, expensive and highly impractical process to implement and as such the possibilities have been limited in this field.

QKD via low-Earth orbit satellites proves to be a more realistic option. Yet while tests have been carried out in China and Japan, these have used expensive satellites and large telescopes. As such, there are still significant challenges in delivering a practical, widespread network with global application.

There have been major developments in space-based QKD, yet as of yet the ground element has been relatively less explored.

Fuelling Innovation

Dr Ross Donaldson, from the Institute of Photonics and Quantum Sciences, will lead the development and feasability testing for the technology. The development will also be aided by companies seeking to commercialise QKD.

He highlighted the groundbreaking potential of this project, stating: “Current ground receivers cost in the region of a million pounds, are specially built and generally need staff to run them.

“However, we are developing ground receiver technology with the aim of significantly reducing that cost. It will be fully autonomous so that its commercially viable and has widespread applications.”

The economic benefits, he added, are promising and could enable Scotland to further develop its space industry.

“Having an increase in ground network coverage will benefit the Scottish economy,” he said. “Enabling us to push for increased coverage in space with micro and nanosatellites.

“This will have a positive economic effect for local nanosatellite suppliers such as Clyde Space.”

Dr Donaldson is funded through a RAEng Research Fellowship from The Royal Academy of Engineering and an additional grant ESPRC. The project will see Heriot-Watt collaborate with the ESPRC Quantum Communications Hub, Arqit, BT, ID Quantique, the University of Edinburgh and the University of Strathclyde.