Related papers: Long-fiber Sagnac interferometers for twin field q…
Semi-quantum key distribution protocols are designed to allow two parties to establish a shared secret key, secure against an all-powerful adversary, even when one of the users is restricted to measuring and preparing quantum states in one…
We demonstrate pulsed operation of a bidirectionally pumped polarization Sagnac interferometric down-conversion source and its generation of narrowband, high-visibility polarization-entangled photons. Driven by a narrowband, mode-locked…
Active optical systems can give rise to intriguing phenomena and applications that are not available in conventional passive systems. Structural rotation has been widely employed to achieve non-reciprocity or time-reversal symmetry…
We propose how to achieve nonreciprocal quantum entanglement of light and motion and reveal its counterintuitive robustness against random losses. We find that by splitting the counterpropagating lights of a spinning resonator via the…
The observation of the Sagnac effect for massive material particles offers a significant enhancement in sensitivity when compared to optical interferometers with equal area and angular rotation velocity. For this reason, there have been…
Owing to its repeater-like rate-loss scaling, twin-field quantum key distribution (TF-QKD) has repeatedly exhibited in laboratory its superiority for secure communication over record fiber lengths. Field trials pose a new set of challenges…
Twin-field quantum key distribution (TF-QKD) elevates the secure key rate from a linear to a square-root dependence on channel loss while preserving measurement-device-independent security. This protocol is uniquely positioned to enable…
Quantum key distribution (QKD), the distribution of quantum secured keys useful for data encryption, is expected to have a crucial impact in the next decades. However, although the notable achievements accomplished in the last twenty years,…
Sagnac speed meter (SSM) topology is known as an alternative technique to reduce quantum back-action in gravitational-wave interferometers. However, any potential imbalance of the main beamsplitter was shown to reduce the quantum noise…
In this paper, we present a fully fiber-based one-way Quantum Key Distribution (QKD) system implementing the Gaussian-Modulated Coherent States (GMCS) protocol. The system employs a double Mach-Zehnder Interferometer (MZI) configuration in…
Original quantum repeater protocols based on single-photon interference suffer from phase noise of the channel, which makes the long-distance quantum communication infeasible. Fortunately, two-photon interference type quantum repeaters can…
Quantum optical Fredkin gate is an indispensable resource for networkable quantum applications. Its performance in practical implementations, however, is limited fundamentally by the inherent quantum fluctuations of the pump waves. We…
Using polarization entangled photon pairs, we demonstrate a robust scheme for quantum illumination and ranging in a lossy environment. Entangled photon pairs are generated in a Sagnac interferometer configuration, yielding high-visibility…
In Quantum Electrodynamics, vacuum becomes a nonlinear optical medium: its optical index should be modified in the presence of intense external electromagnetic fields. The DeLLight project (Deflection of Light by Light) aims to observe this…
Large-scale quantum communication networks are still a huge challenge due to the rate-distance limit of quantum key distribution (QKD). Recently, twin-field (TF) QKD has been proposed to overcome this limit. Here, we prove that…
Entanglement is the basis of many quantum applications. The technically most mature of them, quantum key distribution, harnesses quantum correlations of entangled photons to produce cryptographic keys of provably unbreakable security. A key…
The phase randomized light is one of the key assumptions in the security proof of Bennett-Brassard 1984 (BB84) quantum key distribution (QKD) protocol implemented with an attenuated laser. Though the assumption has been believed to be…
The Sagnac speed meter interferometer topology can potentially provide enhanced sensitivity to gravitational waves in the audio-band compared to equivalent Michelson interferometers. A challenge with the Sagnac speed meter interferometer…
Quantum Key Distribution (QKD) protocols enable two distant parties to communicate with information-theoretically proven secrecy. However, these protocols are generally vulnerable to potential mismatches between the physical modeling and…
Secure key rate (SKR) of point-point quantum key distribution (QKD) is fundamentally bounded by the rate-loss limit. Recent breakthrough of twin-field (TF) QKD can overcome this limit and enables long distance quantum communication, but its…