Empty-Signal Detection and the Principle-Level Feasibility of Arbitrarily Long-Distance Repeaterless Quantum Communication
Abstract
Practical repeaterless quantum communication (PRQC) is fundamentally constrained by the divergence of the quantum bit error rate (QBER) arising from the interplay between channel loss and single-photon detector (SPD) dark counts. As the channel transmission rate decays exponentially with distance, vacuum-induced dark counts inevitably dominate detection events beyond a finite range, driving the QBER toward 50\% and rendering PRQC infeasible. Here, a theoretical framework termed empty-signal detection (ESD) is established to address this long-standing limitation at the level of principle. By encoding particle-existence information (PEI) onto an auxiliary degree of freedom (DOF) and employing controlled operations together with multi-copy analysis, the ESD paradigm enables vacuum-induced detection events to be identified and filtered without disturbing the encoded quantum information. Consequently, the non-empty signal rate (NESR) of the accepted signals can be stabilized at a distance-independent level under physically reasonable conditions, thereby suppressing the fundamental QBER within the secure bounds of PRQC, irrespective of channel attenuation. As a result, PRQC can, in principle, remain feasible over arbitrarily long distances, with the fundamental limitation shifting from distance-dependent QBER divergence to resource-dependent efficiency trade-offs. By providing a rigorous theoretical resolution of the fundamental QBER-induced distance limitation, this work clarifies the principle-level scalability of PRQC. Furthermore, the vacuum-filtering framework developed here may also be of interest in a broader class of loss-sensitive or detection-based quantum tasks.引用本文复制引用
Hao Shu.Empty-Signal Detection and the Principle-Level Feasibility of Arbitrarily Long-Distance Repeaterless Quantum Communication[EB/OL].(2025-12-29)[2026-01-18].https://arxiv.org/abs/2509.15884.学科分类
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