Multiplexing scheme for simplified entanglement-based large-alphabet quantum key distribution

Quantum receiver for large alphabet communication

Quantum mechanics allows measurements that surpass the fundamental sensitivity limits of classical methods. To benefit from the quantum advantage in a practical setting, the receiver should use communication channels resources optimally; this can be done employing large communication alphabets. Here we show the fundamental sensitivity potential of a quantum receiver for coherent communication with frequency shift keying. We introduce an adaptive quantum protocol for this receiver, show that its sensitivity outperforms other receivers for alphabet sizes above 4 and scales favorably, whereas qua…

The limits of multiplexing quantum and classical channels: Case study of a 2.5 GHz discrete variable quantum key distribution system

Network integration of quantum key distribution is crucial for its future widespread deployment due to the high cost of using optical fibers dedicated for the quantum channel, only. We studied the performance of a system running a simplified BB84 protocol at 2.5 GHz repetition rate, operating in the original wavelength band, short O-band, when multiplexed with communication channels in the conventional wavelength band, short C-band. Our system could successfully generate secret keys over a single-mode fiber with a length of 95.5 km and with co-propagating classical signals at a launch power of…

面向超导量子比特可扩展量子信息处理的多路复用控制方案

Multiplexed control scheme for scalable quantum information processing with superconducting qubits

针对超导量子比特传统独立控制布线过多、制约可扩展性的问题，提出结合硬件-软件协同设计、采用频率复用与独立调谐的多路复用控制方案，可简化布线并减少一到两个数量级控制线，提升超导量子处理器可扩展性。

用于科学推广的简单便携式量子密钥分发

Simple portable quantum key distribution for science outreach

本文提出一种基于弱相干脉冲和简化三态BB84协议的紧凑便携QKD教学装置，通过时间复用仅用两个探测器实现自由空间量子密钥分发演示，适合本科生实验教学。