Dynamic distributed quantum sensing of radio-frequency fields via time-bin entanglement

Abstract

We propose a novel framework for discrete-variable (DV) distributed quantum sensing, wherein traditional polarization-based probes are replaced with time-bin entangled qubits. We show that the intrinsic temporal structure of time-bin Bell states can be utilized as a tunable, built-in two-time differential sampling reference for sensing radio-frequency (RF) fields. Unlike existing protocols based on polarization Bell states, which are limited to static measurements, our proposed architecture enables the coherent mapping of dynamic RF phase signals onto static quantum optical phases. By matching the time-bin separation to the RF or intermediate frequency (IF) half-period (antipodal sampling), we theoretically demonstrate that our protocol provides a 6 dB sensitivity enhancement over one-sample static polarization encodings while preserving the 3 dB per-pair entanglement advantage over the separable standard quantum limit benchmark. The performance enhancement is validated with Monte Carlo simulations. This approach provides a solution for RF sensing in DV photonic quantum networks, offering a clear path toward quantum-enhanced and frequency-agile distributed sensor arrays and broader utilization of time-domain quantum probe encodings.