General bounds for sender-receiver capacities in multipoint quantum communications

Laurenza, Riccardo; Pirandola, Stefano

doi:10.1103/physreva.96.032318

Cited by 83 publications

(59 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The AMQD‐MQA allows for several legal parties to perform reliable simultaneous secret communication over a shared physical Gaussian link through the combination of a sophisticated allocation mechanism of the Gaussian subcarriers and the careful utilization of the Gaussian subchannels. The secret key rates and security thresholds of multicarrier transmission have been proven in Gyongyosi and Imre, leading to enhanced secret key rates in both one‐ and two‐way CVQKD . For further information on the bounds of private quantum communications, we suggest Pirandola et al The common root of these improvements is that the additional degrees of freedom injected by the multicarrier transmission act as a resource, allowing for the parties to exceed significantly the possibilities of singe‐carrier CVQKD.…”

Section: Introductionmentioning

confidence: 97%

Diversity space of multicarrier continuous‐variable quantum key distribution

Gyöngyösi

Imre

2019

Int J Communication

View full text Add to dashboard Cite

Summary The diversity space of multicarrier continuous‐variable quantum key distribution (CVQKD) is defined. The diversity space utilizes the resources that are injected into the transmission by the additional degrees of freedom of the multicarrier modulation. We prove that the exploitable extra degree of freedom in a multicarrier CVQKD scenario significantly extends the possibilities of single‐carrier CVQKD. The manifold extraction allows for the parties to reach decreased error probabilities by utilizing those extra resources of a multicarrier transmission that are not available in a single‐carrier CVQKD setting. We define the multidimensional manifold space of multicarrier CVQKD and the optimal tradeoff between the available degrees of freedom of the multicarrier transmission. We extend the manifold extraction for the multiple‐access AMQD‐MQA (multiuser quadrature allocation) multicarrier protocol. The additional resources of multicarrier CVQKD allow the achievement of significant performance improvements that are particularly crucial in an experimental scenario.

show abstract

Section: Introductionmentioning

confidence: 97%

Diversity space of multicarrier continuous‐variable quantum key distribution

Gyöngyösi

Imre

2019

Int J Communication

View full text Add to dashboard Cite

show abstract

“…Free‐space optical (FSO) quantum links provide a tool to implement quantum communications via wireless telecommunication network infrastructures. As an integrated component of future quantum Internet and long‐distance quantum communications, the FSO quantum channels could play a significant role in the global‐scale practical implementations of quantum communications and quantum key distribution (QKD) . QKD systems allow us to utilize the fundamentals of quantum mechanics to realize unconditionally secure communications for legal users.…”

Section: Introductionmentioning

confidence: 99%

“…As an integrated component of future quantum Internet 11-16 and long-distance quantum communications, 11,17-29 the FSO quantum channels could play a significant role in the global-scale practical implementations of quantum communications and quantum key distribution (QKD). [1][2][3][30][31][32][33][34][35][36][44][45][46][47][48][49] QKD systems allow us to utilize the fundamentals of quantum mechanics to realize unconditionally secure communications for legal users. QKD protocols can be decomposed into discrete-variable (DV) and continuous-variable (CV) counterparts.…”

mentioning

confidence: 99%

Secret key rates of free‐space optical continuous‐variable quantum key distribution

Gyöngyösi

Imre

2019

Int J Communication

View full text Add to dashboard Cite

Summary In this letter, we derive the maximal achievable secret key rates for continuous‐variable quantum key distribution (CVQKD) over free‐space optical (FSO) quantum channels. We provide a channel decomposition for FSO‐CVQKD quantum channels and study the SNR (signal‐to‐noise ratio) characteristics. The analytical derivations focus particularly on the low‐SNR scenarios. The results are convenient for wireless quantum key distribution and for the quantum Internet.

show abstract

“…This issue has been addressed in [32] and [24], where the authors obtained network versions of equation (2), by respectively using E R or E sq as measures of entanglement. The possibility of dealing with quantum broadcast channels [33] has also been considered in [34][35][36][37][38][39]. When multiple channels are involved, a typical approach consists in splitting the whole network into two parts, and then in using the maximum amount of entanglement generated by the channels connecting them in order to bound the number of ebits (pbits) produced by a communication protocol.…”

mentioning

confidence: 99%

Versatile relative entropy bounds for quantum networks

Rigovacca¹,

Kato²,

Bäuml³

et al. 2018

New J. Phys.

View full text Add to dashboard Cite

We provide a versatile upper bound on the number of maximally entangled qubits, or private bits, shared by two parties via a generic adaptive communication protocol over a quantum network when the use of classical communication is not restricted. Although our result follows the idea of Azuma et al (2016 Nat. Commun. 7 13523) of splitting the network into two parts, our approach relaxes their strong restriction, consisting of the use of a single entanglement measure in the quantification of the maximum amount of entanglement generated by the channels. In particular, in our bound the measure can be chosen on a channel-by-channel basis, in order to make it as tight as possible. This enables us to apply the relative entropy of entanglement, which often gives a state-of-the-art upper bound, on every Choi-simulable channel in the network, even when the other channels do not satisfy this property. We also develop tools to compute, or bound, the max-relative entropy of entanglement for channels that are invariant under phase rotations. In particular, we present an analytical formula for the max-relative entropy of entanglement of the qubit amplitude damping channel. IntroductionWhenever two parties, say Alice and Bob, want to communicate by using a quantum channel, its noise unavoidably limits their communication efficiency [1]. In the limit of many channel uses, their asymptotic optimal performance can be quantified by the channel capacity, which represents the supremum of the number of qubits/bits that can be faithfully transmitted per channel use. Obtaining an exact expression for this quantity is typically far from trivial. Indeed, in addition to the difficulty of studying the asymptotic behaviour of the channel, the value of the capacity also depends on the task Alice and Bob want to perform, as well as on the free resources available to them [1]. Two representative tasks, which will be considered in our paper, involve the generation and distribution of a string of shared private bits (pbits) [2,3] or of maximally entangled states (ebits) [4]. These are known to be fundamental resources for more complex protocols, such as secure classsical communication [5,6], quantum teleportation [7], and quantum state merging [8]. An example of free resource involves the possibility of exchanging classical information over a public classical channel, such as a telephone line or over the internet. Depending on the restrictions on this, the capacity is said to be assisted by zero, forward, backward, or two-way classical communication [1]. In this paper we will focus on the last option, that is, no restriction will be imposed on the use of classical communication.Although the capacity of a quantum channel is by definition an abstract and theoretical quantity, it is also practically useful in that it can be compared with the performance of known transmission schemes. This comparison could then give an indication on the extent of improvements that could be expected in the future. From this perspective, similar conclusions could be obt...

show abstract

General bounds for sender-receiver capacities in multipoint quantum communications

Cited by 83 publications

References 67 publications

Diversity space of multicarrier continuous‐variable quantum key distribution

Diversity space of multicarrier continuous‐variable quantum key distribution

Secret key rates of free‐space optical continuous‐variable quantum key distribution

Versatile relative entropy bounds for quantum networks

Contact Info

Product

Resources

About