Quantum Communication and Sensing in the Microwave Regime

Interest in using microwave modes for quantum communication and sensing is surging, driven by their potential applications ranging from fundamental physics to practical use in both quantum and classical technologies.

In basic science, microwave quantum-limited detectors, such as efficient photocounters, are key elements for dark matter search and fundamental tests of quantum mechanics. In the context of superconducting quantum technologies, quantum-enhanced microwave sensors could substantially improve readout performance, while microwave quantum communication protocols offer a pathway for integrating separate quantum processing units. From an engineering perspective, microwave frequencies belong to the low-energy spectrum, useful for non-invasive material analysis and sustainable paradigms such as backscatter communication.

This Focus Collection aims to bring together cutting-edge experimental and theoretical developments in the rapidly evolving field of microwave quantum communication and sensing. The scope includes but is not limited to:

• The design of protocols specific for microwave modes;
• The development of formal theoretical tools for characterisation and benchmarking of microwave quantum technologies;
• Experimental demonstrations of quantum communication and sensing protocols, ranging from proof-of-principle to high technological readiness level;
• The development and characterisation of new superconducting, electromechanical, and hybrid super/semi-conductor devices for manipulation and measurement of microwave signals.