Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:quant-ph/0208117 · Physical Review A

Unconditional continuous-variable dense coding

Timothy C. Ralph, Elanor H. Huntington

Published Oct 24, 2002• 51 citations
arXivHTMLPDF

Abstract

We investigate the conditions under which unconditional dense coding can be achieved using continuous-variable entanglement. We consider the effect of entanglement impurity and detector efficiency and discuss experimental verification. We conclude that the requirements for a strong demonstration are not as stringent as previously thought, and are within the reach of present technology.

DOI
10.1103/physreva.66.042321

Related papers

Dense coding for continuous variables

Samuel L. Braunstein, Harry J. Kimble

A scheme to achieve dense quantum coding for the quadrature amplitudes of the electromagnetic field is presented. The protocol utilizes shared entanglement provided by nondegenerate parametric down-conversion in the limit of large gain to attain high efficiency. For a constraint in the mean number of photons $\mathrm{n\ifmmode \bar{}\else \={}\fi{}}$ associated with modulation in the signal channel, the channel capacity for dense coding is found to be $\mathrm{ln}(1+\mathrm{n\ifmmode \bar{}\else \={}\fi{}}+{n}^{2}),$ which always beats coherent-state communication and surpasses squeezed-state communication for $\mathrm{n\ifmmode \bar{}\else \={}\fi{}}>1.$ For $\mathrm{n\ifmmode \bar{}\else \={}\fi{}}\ensuremath{\gg}1,$ the dense coding capacity approaches twice that of either scheme.

arXiv:quant-ph/9910010•Physical Review A•Mar 3, 2000•460 citations

Nonclassical Light Fields and Their Application in Quantum Information

Kunchi Peng

We briefly summarized the experimental generation scheme of the optical entangle states for continuous variables and their applications in quantum teleportation,quantum dense coding,controlled dense coding,entanglement swapping and quantum communication network.

Journal of Shanxi University•Jan 1, 2007•0 citations

Advances in Quantum Dense Coding

Yu Guo, Bi‐Heng Liu, Chuan‐Feng Li +1 more

Abstract Quantum dense coding is one of the most important protocols in quantum communication. It derives from the idea of using quantum resources to boost the communication capacity and now serves as a key primitive across a variety of quantum information protocols. This Progress Report focuses on the basic theoretical ideas behind quantum dense coding, discussing its development history from discrete and continuous variables to quantum networks, then to its variant protocols and applications in quantum secure communication. With this basic background in hand, then the main experimental achievements are reviewed, from photonic qubits and qudits to optical modes, nuclear magnetic resonance, and atomic systems. Besides the state of the art, finally potential future steps are discussed.

arXiv:1904.12252•Advanced Quantum Technologies•Apr 29, 2019•75 citations

Experimental Demonstration of Tripartite Entanglement and Controlled Dense Coding for Continuous Variables

Jietai Jing, Jing Zhang, Ying Lin Yan +3 more

A tripartite entangled state of bright optical field is experimentally produced using an Einstein-Podolsky-Rosen entangled state for continuous variables and linear optics. The controlled dense coding among a sender, a receiver, and a controller is demonstrated by exploiting the tripartite entanglement. The obtained three-mode "position" correlation and relative "momentum" correlation between the sender and the receiver, and thus the improvements of the measured signal to noise ratios of amplitude and phase signals with respect to the shot noise limit are 3.28 and 3.18 dB, respectively. If the mean photon number n equals 11 the channel capacity can be controllably inverted between 2.91 and 3.14. When n is larger than 1.0 and 10.52, the channel capacity of the controlled dense coding is predicted to exceed the ideal single channel capacity of coherent and squeezed state light communication, respectively.

arXiv:quant-ph/0210132•Physical Review Letters•Apr 23, 2003•362 citations

Experimental demonstration of entanglement-assisted coding using a two-mode squeezed vacuum state

Jun Mizuno, Kentaro Wakui, Akira Furusawa +1 more

We have experimentally realized the scheme initially proposed as quantum dense coding with continuous variables [Ban, J. Opt. B: Quantum Semiclassical Opt. 1, L9 (1999); Braunstein and Kimble, Phys. Rev. A 61, 042302 (2000)]. In our experiment, a pair of EPR (Einstein-Podolsky-Rosen) beams is generated from two independent squeezed vacua. After adding a two-quadrature signal to one of the EPR beams, two squeezed beams that contain the signal were recovered. Although our squeezing level is not sufficient to demonstrate the channel capacity gain over the Holevo limit of a single-mode channel without entanglement, our channel is superior to conventional channels such as coherent and squeezing channels. In addition, the optical addition and subtraction processes demonstrated are elementary operations of universal quantum information processing on continuous variables.

arXiv:quant-ph/0402040•Physical Review A•Jan 4, 2005•79 citations

Dense coding in entangled states

Hyuk‐Jae Lee, Doyeol Ahn, Sung Woo Hwang

We consider the dense coding of entangled qubits shared between two parties, Alice and Bob. The efficiency of classical information gain through quantum entangled qubits is also considered for the case of pairwise entangled qubits and maximally entangled qubits. We conclude that using the pairwise entangled qubits can be more efficient when two parties communicate whereas using the maximally entangled qubits can be more efficient when the N parties communicate.

Physical Review A•Aug 5, 2002•69 citations
We investigate the conditions under which unconditional dense coding can be achieved using continuous-variable entanglement. We consider the effect of entanglement impurity and detector efficiency and discuss experimental verification. We conclude that the requirements for a strong demonstration are not as stringent as previously thought, and are within the reach of present technology.
A scheme to achieve dense quantum coding for the quadrature amplitudes of the electromagnetic field is presented. The protocol utilizes shared entanglement provided by nondegenerate parametric down-conversion in the limit of large gain to attain high efficiency. For a constraint in the mean number of photons $\mathrm{n\ifmmode \bar{}\else \={}\fi{}}$ associated with modulation in the signal channel, the channel capacity for dense coding is found to be $\mathrm{ln}(1+\mathrm{n\ifmmode \bar{}\else \={}\fi{}}+{n}^{2}),$ which always beats coherent-state communication and surpasses squeezed-state communication for $\mathrm{n\ifmmode \bar{}\else \={}\fi{}}>1.$ For $\mathrm{n\ifmmode \bar{}\else \={}\fi{}}\ensuremath{\gg}1,$ the dense coding capacity approaches twice that of either scheme.
Abstract Quantum dense coding is one of the most important protocols in quantum communication. It derives from the idea of using quantum resources to boost the communication capacity and now serves as a key primitive across a variety of quantum information protocols. This Progress Report focuses on the basic theoretical ideas behind quantum dense coding, discussing its development history from discrete and continuous variables to quantum networks, then to its variant protocols and applications in quantum secure communication. With this basic background in hand, then the main experimental achievements are reviewed, from photonic qubits and qudits to optical modes, nuclear magnetic resonance, and atomic systems. Besides the state of the art, finally potential future steps are discussed.
A tripartite entangled state of bright optical field is experimentally produced using an Einstein-Podolsky-Rosen entangled state for continuous variables and linear optics. The controlled dense coding among a sender, a receiver, and a controller is demonstrated by exploiting the tripartite entanglement. The obtained three-mode "position" correlation and relative "momentum" correlation between the sender and the receiver, and thus the improvements of the measured signal to noise ratios of amplitude and phase signals with respect to the shot noise limit are 3.28 and 3.18 dB, respectively. If the mean photon number n equals 11 the channel capacity can be controllably inverted between 2.91 and 3.14. When n is larger than 1.0 and 10.52, the channel capacity of the controlled dense coding is predicted to exceed the ideal single channel capacity of coherent and squeezed state light communication, respectively.
We have experimentally realized the scheme initially proposed as quantum dense coding with continuous variables [Ban, J. Opt. B: Quantum Semiclassical Opt. 1, L9 (1999); Braunstein and Kimble, Phys. Rev. A 61, 042302 (2000)]. In our experiment, a pair of EPR (Einstein-Podolsky-Rosen) beams is generated from two independent squeezed vacua. After adding a two-quadrature signal to one of the EPR beams, two squeezed beams that contain the signal were recovered. Although our squeezing level is not sufficient to demonstrate the channel capacity gain over the Holevo limit of a single-mode channel without entanglement, our channel is superior to conventional channels such as coherent and squeezing channels. In addition, the optical addition and subtraction processes demonstrated are elementary operations of universal quantum information processing on continuous variables.