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تسجيل مستخدم جديدA direct GHz-clocked phase and intensity modulated transmitter applied to quantum key distribution
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Quantum key distribution (QKD), a technology that enables perfectly secure communication, has evolved to the stage where many different protocols are being used in real-world implementations. Each protocol has its own advantages, meaning that users can choose the one best-suited to their application, however each often requires different hardware. This complicates multi-user networks, in which users may need multiple transmitters to communicate with one another. Here, we demonstrate a direct-modulation based transmitter that can be used to implement most weak coherent pulse based QKD protocols with simple changes to the driving signals. This also has the potential to extend to classical communications, providing a low chirp transmitter with simple driving requirements that combines phase shift keying with amplitude shift keying. We perform QKD with concurrent time-bin and phase modulation, alongside phase randomisation. The acquired data is used to evaluate secure key rates for time-bin encoded BB84 with decoy states and a finite key-size analysis, giving megabit per second secure key rates, 1.60 times higher than if purely phase-encoded BB84 was used.
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Signal state preparation in quantum key distribution schemes can be realized using either an active or a passive source. Passive sources might be valuable in some scenarios; for instance, in those experimental setups operating at high transmission ra
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onment. A time-cost analysis of the sifted, error-corrected, and secret key rates relative to the raw key rate is presented, and the scalability of our implementation with respect to higher secret key rates is discussed.
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y scheme and finite-key analysis, we achieve record breaking secret key rates of 1.5 kbps over 200 km of standard optical fiber.
Measurement-device-independent quantum key distribution (MDI-QKD) is a technique for quantum-secured communication that eliminates all detector side-channels, although is currently limited by implementation complexity and low secure key rates. Here,
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