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Estimation of quantum channels with finite resources [article]

Markus A. Cirone, Aldo Delgado, Dietmar G. Fischer, Matthias Freyberger, Holger Mack, Michael Mussinger
2001 arXiv   pre-print
It is assumed that the users of the channel have at best only partial knowledge of it and make use of a finite amount of resources to estimate it.  ...  It turns out that the use of entangled particles as a new kind of nonclassical resource enhances the estimation quality of some classes of quantum channel.  ...  ACKNOWLEDGMENTS We acknowledge support by the DFG programme "Quanten-Informationsverarbeitung", by the European Science Foundation QIT programme and by the programmes "QUBITS" and "QUEST" of the European  ... 
arXiv:quant-ph/0108037v1 fatcat:lef3envckngq7fqkf57jrayh5u

Transfer of quantum states using finite resources

Dietmar G. Fischer, Holger Mack, Matthias Freyberger
2001 Physical Review A. Atomic, Molecular, and Optical Physics  
We discuss the problem of transfering a qubit from Alice to Bob using a noisy quantum channel and only finite resources. As the basic protocol for the transfer we apply quantum teleportation.  ...  It turns out that for a certain quality of the channel direct teleportation combined with qubit purification is superior to entanglement purification of the channel.  ...  ACKNOWLEDGMENTS We acknowledge support by the DFG programme "Quanten-Informationsverarbeitung", by the European Science Foundation QIT programme and by the programmes "QUBITS" and "QUEST" of the European  ... 
doi:10.1103/physreva.63.042305 fatcat:ydu4frdmjbbhhk63rqsimopo7u

Channel Simulation in Quantum Metrology [article]

Riccardo Laurenza, Cosmo Lupo, Gaetana Spedalieri, Samuel L. Braunstein, Stefano Pirandola
2018 arXiv   pre-print
In this review we discuss how channel simulation can be used to simplify the most general protocols of quantum parameter estimation, where unlimited entanglement and adaptive joint operations may be employed  ...  For these channels, we may express the quantum Cram\'er Rao bound directly in terms of their Choi matrices.  ...  This work has been supported by the Innovation Fund Denmark (Qubiz project), the European Union (MSCA-IF-2016), and the EPSRC via the 'UK Quantum Communications Hub' (EP/M013472/1). S. P. thanks R.  ... 
arXiv:1712.06603v2 fatcat:cjkwh7h5tzd67p2zv7uo4jhely

Enhanced estimation of a noisy quantum channel using entanglement

Dietmar G. Fischer, Holger Mack, Markus A. Cirone, Matthias Freyberger
2001 Physical Review A. Atomic, Molecular, and Optical Physics  
We discuss the estimation of channel parameters for a noisy quantum channel - the so-called Pauli channel - using finite resources.  ...  It turns out that prior entanglement considerably enhances the fidelity of the estimation when we compare it to an estimation scheme based on separable quantum states.  ...  ACKNOWLEDGMENTS We acknowledge discussions with G. Alber, A. Delgado, and M.  ... 
doi:10.1103/physreva.64.022309 fatcat:iw5rbmgx45dvhfmrrhrjc4vrw4

Quantum Cryptography with Finite Resources: Unconditional Security Bound for Discrete-Variable Protocols with One-Way Postprocessing

Valerio Scarani, Renato Renner
2008 Physical Review Letters  
We derive a bound for the security of QKD with finite resources under one-way post-processing, based on a definition of security that is composable and has an operational meaning.  ...  For any other discrete-variable protocol, unconditional security can be obtained using the exponential de Finetti theorem, but the additional overhead leads to very pessimistic estimates.  ...  In this Letter, we provide a security bound for discrete-variable QKD protocols with finite resources and with respect to a composable security definition, based on the formalism developed by one of us  ... 
doi:10.1103/physrevlett.100.200501 pmid:18518517 fatcat:y5ea3mm7l5agbcv2s7ep3fjkhq

Nonthermal Quantum Channels as a Thermodynamical Resource

Miguel Navascués, Luis Pedro García-Pintos
2015 Physical Review Letters  
We find that, in the limit of asymptotically many uses of each channel, the distillable work is an additive function of the considered channels, computable for both finite dimensional quantum operations  ...  Quantum thermodynamics can be understood as a resource theory, whereby thermal states are free and the only allowed operations are unitary transformations commuting with the total Hamiltonian of the system  ...  Hence, states with finite energy correspond to states with finite first and second moments.  ... 
doi:10.1103/physrevlett.115.010405 pmid:26182086 fatcat:4yaqodxugvgrvbc52tmaodhxpy

Finite-error metrological bounds on multiparameter Hamiltonian estimation

Naoto Kura, Masahito Ueda
2018 Physical Review A  
By comparing the cases with different numbers of Hamiltonian channels, we also find that the few-channel procedure with adaptive feedback and the many-channel procedure with entanglement are equivalent  ...  in that they require the same amount of time resource up to a constant factor.  ...  In particular, we find that the time resource scales with δ −1 , which explicitly shows the quantum-metrological limit.  ... 
doi:10.1103/physreva.97.012101 fatcat:bp7cklflpjgclgxrnrrcem4wdi

Finite-resource teleportation stretching for continuous-variable systems [article]

Riccardo Laurenza, Samuel L. Braunstein, Stefano Pirandola
2018 arXiv   accepted
We show how adaptive protocols of quantum and private communication through bosonic Gaussian channels can be simplified into much easier block versions that involve resource states with finite energy.  ...  Commun. 8, 15043 (2017)], based on teleportation stretching and relative entropy of entanglement, with an alternative simulation of Gaussian channels recently introduced by Liuzzo-Scorpo et al.  ...  Mari for discussions on the relations between the various bounds, and the finite-resource simulation of the pure-loss channel. The authors also thank C. Lupo, G. Spedalieri, C. Ottaviani, S.  ... 
arXiv:1706.06065v3 fatcat:oilmsgkv35h5vhbqxykbv43qci

Quantum key distribution with finite resources: Taking advantage of quantum noise

Markus Mertz, Hermann Kampermann, Zahra Shadman, Dagmar Bruß
2013 Physical Review A. Atomic, Molecular, and Optical Physics  
We study the situation where quantum noise is added deliberately, and investigate the remarkable benefit for the finite key rate.  ...  We compare the effect of different noise scenarios on the achievable rate of an epsilon-secure key for the BB84 and the six-state protocol.  ...  The purpose of this article is to investigate the effect of quantum noise on secret key rates with finite resources for the BB84 [23] and six-state protocol [21, 22] .  ... 
doi:10.1103/physreva.87.042312 fatcat:k4mk7mxe3rezng336pcingngo4

Selective Efficient Quantum Process Tomography [article]

Ariel Bendersky, Fernando Pastawski, Juan Pablo Paz
2008 arXiv   pre-print
We present a new method for quantum process tomography. The method enables us to efficiently estimate, with fixed precision, any of the parameters characterizing a quantum channel.  ...  Also, we show how to efficiently estimate all the average survival probabilities associated with the channel (i.e., all the diagonal elements of its χ--matrix.  ...  Direct Characterization of Quantum Dynamics (DCQD) was recently proposed [3, 4] and it requires an extra ancillary system of n clean qubits with a clean quantum channel.  ... 
arXiv:0801.0758v1 fatcat:57qzxyx4cngxfnaqng5lgzqhya

Unified quantum convolutional coding

Mark M. Wilde, Todd A. Brun
2008 2008 IEEE International Symposium on Information Theory  
The use of these diverse resources gives our technique the benefits of both active and passive quantum error correction.  ...  Our goal is to provide a framework for designing codes that approach the "grandfather" capacity of an entanglement-assisted quantum channel for sending classical and quantum information simultaneously.  ...  One useful line of investigation may be to combine this theory with the recent quantum turbo-coding theory [21] .  ... 
doi:10.1109/isit.2008.4595008 dblp:conf/isit/WildeB08 fatcat:jmfuwffxojbatcyrwkk4cine3a

Coherence and quantum correlations measure sensitivity to dephasing channels [article]

Benjamin Yadin, Pieter Bogaert, Cristian E. Susa, Davide Girolami
2018 arXiv   pre-print
That is, coherence is the ability to estimate a dephasing channel, quantified by the quantum Fisher information.  ...  We introduce measures of quantum coherence as the speed of evolution of a system under decoherence.  ...  Namely, both are valuable resources for estimating the strength of a dephasing channel, a metrology primitive which plays a key role in the characterisation of quantum dynamics [13, 14] , quantum device  ... 
arXiv:1810.02795v1 fatcat:zcuou6iaerfsraxk3mpbbfjzsu

Repeatable quantum memory channels

Tomáš Rybár, Mário Ziman
2008 Physical Review A. Atomic, Molecular, and Optical Physics  
Within the framework of quantum memory channels we introduce the notion of repeatability of quantum channels.  ...  In particular, a quantum channel is called repeatable if there exist a memory device implementing the same channel on each individual input.  ...  TR acknowledges the support of the project APVV LPP-0264-07.  ... 
doi:10.1103/physreva.78.052114 fatcat:x6clpanznfa3jg74omoqynl7ka

Selective and efficient quantum process tomography with single photons [article]

Christian Tomás Schmiegelow, Miguel Antonio Larotonda, Juan Pablo Paz
2010 arXiv   pre-print
Lett 100, 190403 (2008)) enables the estimation of any element of the chi-matrix that characterizes a quantum process using resources that scale polynomially with the number of qubits.  ...  It is based on the idea of mapping the estimation of any chi-matrix element onto the average fidelity of a quantum channel and estimating the latter by sampling randomly over a special set of states called  ...  Lett 100, 190403 (2008) ) enables the estimation of any element of the chi-matrix that characterizes a quantum process using resources that scale polynomially with the number of qubits.  ... 
arXiv:1002.4436v1 fatcat:pjuemvwy4jffre2anvssc7cooq

Finite resource performance of small satellite-based quantum key distribution missions [article]

Tanvirul Islam and Jasminder S. Sidhu and Brendon L. Higgins and Thomas Brougham and Tom Vergoossen and Daniel K. L. Oi and Thomas Jennewein and Alexander Ling
2022 arXiv   pre-print
, improving on estimates based on older finite key bounds.  ...  High channel loss may decrease the signal-to-noise ratio due to background noise, reduce the number of generated raw key bits, and increase the quantum bit error rate (QBER), all of which have detrimental  ...  Quantum channel configuration for three different SatQKD missions.  ... 
arXiv:2204.12509v1 fatcat:h62iumubgrhovager4dtcaksxm
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