A hybrid atom-superconductor interface for quantum networking

Hybrid quantum systems combine two or more disparate quantum technologies to harness their individual strengths and overcome the limitations of each qubit type. Superconducting circuits are promising candidates for quantum processors as they perform fast high-fidelity gate operations but have short coherence times. Neutral atoms have the potential to fulfill the requirement for coherent storage of quantum information. Atomic transitions occur in both, the microwave and optical frequency range. Therefore, nodular quantum systems consisting of memory and processor qubits could be connected via optical channels to form a quantum network. The properties of atoms in highly excited Rydberg states in theory enable microwave cavity mediated long-distance entanglement between atomic ensembles and highly directional photon emission.

The aim of this project is to develop a high-fidelity interface between superconducting and photonic qubits to realise an expansive quantum networking architecture. The long-term goal of this research is to advance the progress of circuit-QED quantum computing approaches with the inclusion of coherent quantum information storage and microwave-to-optical conversion. Therefore, generation of a chip-based device where atoms are coupled to superconducting circuits via a superconducting microwave resonator enables and deterministic entanglement of photonic qubits. Trapping atomic ensembles above a superconducting coplanar waveguide (CPW) and generating long-distance entanglement remains experimentally challenging but is an essential requirement to build a scalable quantum network.

Quantum technologies promise a transformation of the fields of measurement, communication and information processing. They present a particular opportunity since they are disruptive technologies: not only do they offer a chance for rapid growth but they also allow lesser participants in a field (such as the UK in IT) to become major players through appropriate risk-taking and manpower development. Students graduating from the InQuBATE Skills Hub will have the right mindset to work in the industries where quantum technologies will be applied, and help to break down the traditional barriers between those sectors to make this transformation happen. They will have all the necessary technical and transferable skills, plus a network of contacts with our partners, their fellow cohort members and the academic supervisors.

Our commercial partners are keen to help our students realise their potential and achieve the impact we expect of them, through the training they offer and their contributions to the centre's research. They include companies who have already developed quantum technologies to products in quantum communication (Toshiba) and optimization (D-Wave), large corporates who are investing in quantum technology because they see its potential to transform their businesses in aerospace, defence, instrumentation and internet services (Lockheed Martin, Google,) and government agencies with key national responsibilities (NPL). We want to see the best communication of our students' research, so our students will benefit from the existing training programme set up with a leading scientific publisher (Nature Publishing Group); we also want to see more of the future companies that lead this field based the UK, so we have partnered with venture capital group DFJ Esprit to judge and mentor the acceleration of our students' innovations toward the market.