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Related papers: Characterization of phase-averaged coherent states

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Quantum key distribution provides secure keys with information-theoretic security ensured by the principle of quantum mechanics. The continuous-variable version of quantum key distribution using coherent states offers the advantages of its…

Quantum Physics · Physics 2024-07-09 Yichen Zhang , Yiming Bian , Zhengyu Li , Song Yu , Hong Guo

The Kennedy-like receiver is a quasi-optimal receiver employed in binary phase-shift-keyed communication schemes with coherent states. It is based on the interference of the two signals encoding the message with a reference local oscillator…

Quantum Physics · Physics 2016-11-15 Matteo Bina , Alessia Allevi , Maria Bondani , Stefano Olivares

We present an improved phase estimation scheme employing entangled coherent states and demon- strate that the states give the smallest variance in the phase parameter in comparison to NOON, BAT and "optimal" states under perfect and lossy…

Quantum Physics · Physics 2011-11-30 Jaewoo Joo , William J. Munro , Timothy P. Spiller

We have designed and realized a prototype that implements a continuous-variable quantum key distribution protocol based on coherent states and reverse reconciliation. The system uses time and polarization multiplexing for optimal…

In this paper, the generalized coherent state for quantum systems with degenerate spectra is introduced. Then, the nonclassicality features and number-phase entropic uncertainty relation of two particular degenerate quantum systems are…

Quantum Physics · Physics 2015-03-17 G. R. Honarasa , M. K. Tavassoly , M. Hatami , R. Roknizadeh

Decoy-state quantum key distribution (QKD) is undoubtedly the most efficient solution to handle multi-photon signals emitted by laser sources, and provides the same secret key rate scaling as ideal single-photon sources. It requires,…

Quantum Physics · Physics 2023-12-22 Xoel Sixto , Guillermo Currás-Lorenzo , Kiyoshi Tamaki , Marcos Curty

We address quantum communication channels based on phase modulation of coherent states and analyze in details the effects of static and dynamical (stochastic) phase diffusion. We evaluate mutual information for an ideal phase receiver and…

Quantum Physics · Physics 2015-10-27 Jacopo Trapani , Berihu Teklu , Stefano Olivares , Matteo G. A. Paris

Quantum versions of cylindric phase space, like for the motion of a particle on the circle, are obtained through different families of coherent states. The latter are built from various probability distributions of the action variable. The…

Quantum Physics · Physics 2015-06-03 I. Aremua , J. P. Gazeau , M. N. Hounkonnou

We present a full experimental characterization of continuous variable quantum communication channels established by shared entanglement together with local operations and classical communication. The resulting teleportation channel was…

Quantum Physics · Physics 2009-11-13 James DiGuglielmo , Boris Hage , Alexander Franzen , Jaromir Fiurasek , Roman Schnabel

The performance of quantum key distribution (QKD) is severely limited by multiphoton emissions, due to the photon-number-splitting attack. The most efficient solution, the decoy-state method, requires that the phases of all transmitted…

Generalized quantum measurements identifying non-orthogonal states without ambiguity often play an indispensable role in various quantum applications. For such unambiguous state discrimination scenario, we have a finite probability of…

Quantum Physics · Physics 2021-04-16 Shuro Izumi , Jonas S. Neergaard-Nielsen , Ulrik L. Andersen

The achievable rate of information transfer in optical communications is determined by the physical properties of the communication channel, such as the intrinsic channel noise. Bosonic phase-noise channels, a class of non-Gaussian…

Quantum Physics · Physics 2019-08-08 M. T. DiMario , L. Kunz , K Banaszek , F. E. Becerra

We develop a general theory for quantum key distribution (QKD) in both the forward error correction and the reverse error correction cases when the QKD system is equipped with phase-randomized coherent light with arbitrary number of decoy…

Quantum Physics · Physics 2009-11-13 Masahito Hayashi

Quantum secret sharing (QSS) is one of the basic communication primitives in future quantum networks which addresses part of the basic cryptographic tasks of multiparty communication and computation. Nevertheless, it is a challenge to…

Quantum Physics · Physics 2023-05-11 Ao Shen , Xiao-Yu Cao , Yang Wang , Yao Fu , Jie Gu , Wen-Bo Liu , Chen-Xun Weng , Hua-Lei Yin , Zeng-Bing Chen

We investigate the performance of several continuous-variable quantum key distribution protocols in the presence of fading channels. These are lossy channels whose transmissivity changes according to a probability distribution. This is…

Quantum Physics · Physics 2018-03-21 Panagiotis Papanastasiou , Christian Weedbrook , Stefano Pirandola

Networking plays a ubiquitous role in quantum technology. It is an integral part of quantum communication and has significant potential for upscaling quantum computer technologies that are otherwise not scalable. Recently, it was realized…

Quantum phase estimation is a core task in quantum technologies ranging from metrology to quantum computing, where it appears as a key subroutine in various algorithms. Here, we quantitatively connect the performance of phase estimation…

Quantum Physics · Physics 2026-05-11 Felix Ahnefeld , Thomas Theurer , Martin B. Plenio

In this paper we present quantum key distribution protocol that, instead of single qubits, uses mesoscopic coherent states of light $|\alpha\rangle$ to encode bit values of a randomly generated key. Given the reference value…

Quantum Physics · Physics 2017-05-04 G. A. Barbosa , J. van de Graaf , P. Mateus , N. Paunković

When comparing quantum states to each other, it is possible to obtain an unambiguous answer, indicating that the states are definitely different, already after a single measurement. In this paper we investigate comparison of coherent…

Quantum Physics · Physics 2007-05-23 Erika Andersson , Marcos Curty , Igor Jex

We consider continuous-variable quantum key distribution with discrete-alphabet encodings. In particular, we study protocols where information is encoded in the phase of displaced coherent (or thermal) states, even though the results can be…

Quantum Physics · Physics 2021-01-18 Panagiotis Papanastasiou , Stefano Pirandola