MOSQUITO: MObile Spin-based QUantum Information sTOrage

Devices exploiting the principles of quantum mechanics can revolutionize the way we communicate, compute and measure. For example, communication links based on the exchange of single photons can generate secret encryption keys, detecting the presence of possible eavesdroppers. As for classical communication networks, quantum networks require local memories and processing units to store and process information.

MOSQUITO investigates the physics related to the demonstration of a portable multi-qubit quantum networking node based on a compact and scalable silicon carbide (SiC) device. The device enables efficient storage of optical quantum states onto nuclear spins at cryogenic temperature, preserves them up to ambient conditions and is accessible at room temperature.
The envisioned integrated device operates in the near-infrared optical region (close to telecom wavelength) and embeds for the first time spintronic, electronic and photonic functionalities on a single platform compatible with standard industrial processing. This break-through is enabled by the unique properties of silicon carbide, which features colour centres with excellent spin coherence, a bright spin/photon interface and established growth and nano-fabrication techniques.

MOSQUITO will open the way to integrated quantum repeaters compatible with telecom networks. Additionally, it will lay the foundations for portable quantum networking nodes, a technology that could facilitate real-world deployment of quantum-enhanced communication security.

Short-term (< 5years): the semiconductor industry
On the shorter term, this project will mostly impact the semiconductor industry. First of all, my work will improve the understanding of the structure of defects that affect the performance of microelectronic devices. While this is currently studied by theoretical simulations and measurements on large ensembles of defects, my work on single-defect optical spectroscopy are already providing novel information that is averaged out in ensemble experiments. As an example, the long debate in the SiC community about the exact structure of the silicon vacancy defect has only been settled thanks to our recent studies on individual vacancies.
This scientific goals of the project can only be reached by integrating, for the first time, photonic, electronic and spintronic functionalities on a single quantum device. This will require tackling several technological challenges that will push further what can be achieved in a material platform of wide industrial interest. For example, the research line on nano-photonic functionalities can provide new insights and ideas that can find applications also in "classical" photonics. Or, my proposed work on p-i-n junctions operating at cryogenic temperature is relevant for the power electronics effort aimed at integrating power devices with superconducting elements. Additionally this work will drive materials scientists to developp high-purity material, where spin coherence is not limited by interaction with unwanted defects and impurities.
Finally, PhD students and post-docs working on the project will acquire expertise in semiconductor physics, optics, electron spin resonance, high-speed electronics, cryogenics, programming and data analysis. This will help create a skilled work-force for academia and high-tech industry.

Medium-term (5-15 years): portable quantum networking links
In the medium term, portable quantum networking links will facilitate the deployment of secret quantum encryption keys into the real-world, including locations which do not include a specialized fiber link. For example, one could envision encoding photonic quantum states on the portable node in a cryogenic docking station and then physically transporting the device to a different location, while preserving the established entanglement. This can have a ground-breaking impact in extending the range of quantum communication,
While focusing on quantum networking, the techniques developed within this project may in parallel impact the field of spin-based quantum sensing. Single spins are the smallest possible magnetic field sensors, and experiments with nitrogen-vacancy centres in diamond are already providing high measurement sensitivity at the ultimate limits of spatial resolution, for materials science and biological applications.

Long-term (>20 years): global satellite-based quantum communication
The output of this project, integrated with the small low-power cryo-coolers developed by the Science & Technology Facilities Council (with Honeywell-Hymatic) will provide the basis for satellite-based quantum repeaters. Such devices will dramatically extend the range of secure quantum communication, potentially connecting any two locations in the world by combining space optical links, quantum memories and quantum error correction.

The general public
Throughout the activities outlined in "Pathways to Impact", the public will gain awareness of the latest results in quantum physics, the promises of quantum technology and the impact of my own work. This will set them in a position to make conscious informed choices regarding why these activities are worth the taxpayer support.