English
Related papers

Related papers: Continuous-Variable Multiplexed Quantum Repeater N…

200 papers

We extend covert communication to the quantum regime by showing that covert quantum communication is possible over optical channels with noise arising either from the environment or from the sender's lab. In particular, we show that…

Quantum Physics · Physics 2016-12-21 Juan Miguel Arrazola , Valerio Scarani

One of the main open problems in quantum communication is the design of efficient quantum-secured networks. This is a challenging goal, because it requires protocols that guarantee both unconditional security and high communication rates,…

Quantum Physics · Physics 2020-04-08 Carlo Ottaviani , Cosmo Lupo , Riccardo Laurenza , Stefano Pirandola

Quantum key repeater is the backbone of the future Quantum Internet. It is an open problem to determine, for an arbitrary mixed bipartite state shared between the stations of a quantum key repeater, how much key can be generated between its…

Quantum Physics · Physics 2026-03-10 Leonard Sikorski , Karol Horodecki , Łukasz Pawela

Entangled coherent states can be prepared remotely by subtracting non-locally a single photon from two quantum superpositions of coherent states, the so-called "Schroedinger's cat" state. Such entanglement can further be distributed over…

We analyze an entanglement-based quantum key distribution (QKD) architecture that uses a linear chain of quantum repeaters employing photon-pair sources, spectral-multiplexing, linear-optic Bell-state measurements, multi-mode quantum…

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

The continuous-variable version of quantum key distribution (QKD) offers the advantages (over discrete-variable systems) of higher secret key rates in metropolitan areas as well as the use of standard telecom components that can operate at…

We investigate the main limitations which prevent the continuous-variable quantum key distribution protocols from achieving long distances in the finite-size setting. We propose a double-modulation protocol which allows using each state for…

Quantum Physics · Physics 2014-12-22 László Ruppert , Vladyslav C. Usenko , Radim Filip

A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution (QKD). Due to noise in the communication line, QKD is in practice limited to a distance of a few hundred kilometres,…

Quantum Physics · Physics 2015-04-28 Stefan Bäuml , Matthias Christandl , Karol Horodecki , Andreas Winter

We propose a hybrid quantum repeater protocol combining the advantages of continuous and discrete variables. The repeater is based on the previous work of Brask et al. [Phys. Rev. Lett. 105, 160501 (2010)] but we present two ways of…

Quantum Physics · Physics 2013-06-13 J. Borregaard , J. B. Brask , A. S. Sørensen

For discrete memoryless multiple-access channels, we propose a general definition of variable length codes with a measure of the transmission rates at the receiver side. This gives a receiver perspective on the multiple-access channel…

Information Theory · Computer Science 2011-02-28 Stephane Musy

Continuous variable-quantum key distribution (CV-QKD) protocols attract increasing attentions in recent years because they enjoy high secret key rate (SKR) and good compatibility with existing optical communication infrastructure. Classical…

Signal Processing · Electrical Eng. & Systems 2025-09-25 Renzhi Yuan , Zhixing Wang , Shouye Miao , Mufei Zhao , Haifeng Yao , Bin Cao , Mugen Peng

We define an iterative error-minimizing secret key adapting method for multicarrier CVQKD. A multicarrier CVQKD protocol uses Gaussian subcarrier quantum continuous variables (CVs) for the transmission. The proposed method allows for the…

Quantum Physics · Physics 2016-10-11 Laszlo Gyongyosi

Quantum repeaters promise to enable quantum networks over global distances by circumventing the exponential decrease in success probability inherent in direct photon transmission. We propose a realistic, functionally integrated quantum…

Quantum Physics · Physics 2016-03-14 Manuel Uphoff , Manuel Brekenfeld , Gerhard Rempe , Stephan Ritter

We propose an improved two-way continuous-variable quantum key distribution (CV QKD) protocol by adding proper random noise on the receiver's homodyne detection, the security of which is analysed against general collective attacks. The…

Quantum Physics · Physics 2013-05-07 Maozhu Sun , Xiang Peng , Hong Guo

Continuous variable quantum key distribution bears the promise of simple quantum key distribution directly compatible with commercial off the shelf equipment. However, for a long time its performance was hindered by the absence of good…

Quantum Physics · Physics 2025-06-18 Jesus Martinez-Mateo , David Elkouss

A potential quantum internet would open up the possibility of realizing numerous new applications, including provably secure communication. Since losses of photons limit long-distance, direct quantum communication and widespread quantum…

Quantum Physics · Physics 2019-12-18 Daniel Miller , Timo Holz , Hermann Kampermann , Dagmar Bruß

Quantum Key Distribution (QKD) is a cutting-edge communication method that enables secure communication between two parties. Continuous-variable QKD (CV-QKD) is a promising approach to QKD that has several advantages over traditional…

Quantum Physics · Physics 2023-05-26 Andres Ruiz-Chamorro , Daniel Cano , Aida Garcia-Callejo , Veronica Fernandez

Overcoming repeaterless bounds for the secret key rate capacity of quantum key distribution protocols is still a challenge with current technology. D. Luong et al. [Applied Physics B 122, 96 (2016)] proposed a protocol to beat a…

Quantum Physics · Physics 2020-01-22 Róbert Trényi , Norbert Lütkenhaus

We expand the recently discussed continuous-variable quantum key distribution scheme of Heid and Luetkenhaus (2006) to qudits with a lossy but noiseless quantum channel. Postselection methods are used. Secret key rates are calculated in the…

Quantum Physics · Physics 2009-03-12 Ulrich Seyfarth