Addressing the quantum technology gap for THz-band SCQC

Develop practical terahertz-band quantum-compatible components, specifically coherent quantum state sources and sensitive low-noise detectors, to enable the preparation and detection of quantum states necessary for simultaneous classical and quantum communications at terahertz frequencies, thereby realizing SCQC in the THz band.

Background

The paper highlights that, despite advances in classical THz communications, simultaneous classical and quantum communications (SCQC) in the THz band have not progressed due to a lack of mature quantum-compatible hardware. In contrast to the optical and microwave domains, the THz range currently lacks coherent quantum sources and sensitive detectors operating at low noise levels, which are essential for preparing and measuring quantum states for secure communications.

This technology gap blocks the practical implementation of SCQC protocols at THz frequencies, even though the THz band offers attractive features such as ultra-wide bandwidth and compact hardware integration. The authors explicitly characterize the realization of SCQC in the THz band as an open research problem, contingent on breakthroughs in materials and compact, high-speed, quantum-capable electronics.