### ?

## Revisiting quantum discord for two-qubit X states: the error bound to an analytical formula

International Journal of Theoretical Physics. 2015. Vol. 54. No. 9. P. 3340-3349.

In this article, we investigate the error bound of quantum discord, obtained from

the analytic formula of Ali et al. (Phys. Rev. A 81, 042105, 2010) for the case of general

X states and from the analytic formula of Fanchini et al. (Phys. Rev. A 81, 052107, 2010)

for the case of symmetric X states. For this purpose we consider 3-element POVM.We find

that the results of Ali et al. and Fanchini et al. may have the worst-case errors of 0.004565

and 0.0009, respectively.

Priority areas:
mathematics

Language:
English

Min Namkung, Younghun K., Physical Review A: Atomic, Molecular, and Optical physics 2017 Vol. 96 No. 2 P. 022318-1-022318-8

Recently, sequential state discrimination, as a quantum-key distribution protocol, has been proposed for
multiple receivers. A previous study [J. A. Bergou et al., Phys. Rev. Lett. 111, 100501 (2013)] showed that
every receiver could successfully perform a sequential state discrimination of two pure states with identical
prior probabilities. In this study, we extend the sequential state discrimination to ...

Added: November 16, 2020

Min Namkung, Jinho C., Jaehee S. et al., International Journal of Theoretical Physics 2015 Vol. 54 No. 9 P. 3340-3349

In this article, we investigate the error bound of quantum discord, obtained from
the analytic formula of Ali et al. (Phys. Rev. A 81, 042105, 2010) for the case of general
X states and from the analytic formula of Fanchini et al. (Phys. Rev. A 81, 052107, 2010)
for the case of symmetric X states. For this purpose ...

Added: November 16, 2020

Min Namkung, Younghun K., Scientific Reports 2019 Vol. 9 No. 1 P. 19664-1-19664-19

Quantum state discrimination of coherent states has been one of important problems in quantum
information processing. Recently, R. Han et al. showed that minimum error discrimination of two
coherent states can be nearly done by using Jaynes-Cummings Hamiltonian. In this paper, based on the
result of R. Han et al., we propose the methods where minimum error discrimination ...

Added: November 16, 2020

Min Namkung, Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1-16915-18

Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...

Added: November 16, 2020

Min Namkung, Younghun K., Scientific Reports 2018 Vol. 8 No. 1 P. 6515-1-6515-13

Recently, J. A. Bergou et al. proposed sequential state discrimination as a new quantum state
discrimination scheme. In the scheme, by the successful sequential discrimination of a qubit state,
receivers Bob and Charlie can share the information of the qubit prepared by a sender Alice. A merit
of the scheme is that a quantum channel is established between ...

Added: November 16, 2020

Physical Review A: Atomic, Molecular, and Optical physics 2017 Vol. 96 No. 2 P. 022318-1-022318-8

Recently, sequential state discrimination, as a quantum-key distribution protocol, has been proposed for
multiple receivers. A previous study [J. A. Bergou et al., Phys. Rev. Lett. 111, 100501 (2013)] showed that
every receiver could successfully perform a sequential state discrimination of two pure states with identical
prior probabilities. In this study, we extend the sequential state discrimination to ...

Added: November 3, 2020

Scientific Reports 2018 Vol. 8 No. 1 P. 16915-1-16915-18

Sequential state discrimination is a strategy for quantum state discrimination of a sender’s quantum
states when N receivers are separately located. In this report, we propose optical designs that can
perform sequential state discrimination of two coherent states. For this purpose, we consider not
only binary phase-shifting-key (BPSK) signals but also general coherent states, with arbitrary prior
probabilities. Since ...

Added: November 3, 2020

Scientific Reports 2019 Vol. 9 No. 1 P. 19664-1-19664-19

Quantum state discrimination of coherent states has been one of important problems in quantum
information processing. Recently, R. Han et al. showed that minimum error discrimination of two
coherent states can be nearly done by using Jaynes-Cummings Hamiltonian. In this paper, based on the
result of R. Han et al., we propose the methods where minimum error discrimination ...

Added: November 3, 2020

Journal of Physics A: Mathematical and Theoretical 2018 Vol. 51 No. 45 P. 455302-1-455302-15

In this article we investigate the non-classical correlation in a macroscopic
physical system. As a tool, we consider an optical hybrid state that is a micro–
macro entangled state. Our strategy is to study the behavior of non-classical
correlation in an optical hybrid state that may go through noisy channels. We
study the violation of two inequalities, which are ...

Added: November 3, 2020

Scientific Reports 2018 Vol. 8 No. 1 P. 6515-1-6515-13

Recently, J. A. Bergou et al. proposed sequential state discrimination as a new quantum state
discrimination scheme. In the scheme, by the successful sequential discrimination of a qubit state,
receivers Bob and Charlie can share the information of the qubit prepared by a sender Alice. A merit
of the scheme is that a quantum channel is established between ...

Added: November 3, 2020

International Journal of Theoretical Physics 2015 Vol. 54 P. 3340-3349

In this article, we investigate the error bound of quantum discord, obtained from
the analytic formula of Ali et al. (Phys. Rev. A 81, 042105, 2010) for the case of general
X states and from the analytic formula of Fanchini et al. (Phys. Rev. A 81, 052107, 2010)
for the case of symmetric X states. For this purpose ...

Added: November 3, 2020

Min N., Kwon Y., Scientific Reports 2020 Vol. 10 No. 1 P. 8247-1-8247-35

Sequential state discrimination is a strategy for N separated receivers. As sequential state
discrimination can be applied to multiparty quantum key distribution (QKD), it has become one of
the relevant research fields in quantum information theory. Up to now, the analysis of sequential
state discrimination has been confined to special cases. In this report, we consider a generalization ...

Added: November 16, 2020

International Journal of Theoretical Physics 2015 Vol. 54 No. 9 P. 3340-3349

In this article, we investigate the error bound of quantum discord, obtained from
the analytic formula of Ali et al. (Phys. Rev. A 81, 042105, 2010) for the case of general
X states and from the analytic formula of Fanchini et al. (Phys. Rev. A 81, 052107, 2010)
for the case of symmetric X states. For this purpose ...

Added: November 16, 2020

Min Namkung, Younghun K., Journal of Physics A: Mathematical and Theoretical 2018 Vol. 51 No. 45 P. 455302-1-455302-16

In this article we investigate the non-classical correlation in a macroscopic
physical system. As a tool, we consider an optical hybrid state that is a micro–
macro entangled state. Our strategy is to study the behavior of non-classical
correlation in an optical hybrid state that may go through noisy channels. We
study the violation of two inequalities, which are ...

Added: November 16, 2020

International Journal of Theoretical Physics 2015 Vol. 54 No. 9 P. 3340-3349

Added: November 16, 2020

Akhmedov E., Physical Review D - Particles, Fields, Gravitation and Cosmology 2013 Vol. 87 No. 4 P. 044049

Following Krotov and Polyakov [ Nucl. Phys. B849 410 (2011)], we show that in global de Sitter space its isometry is broken by the loop IR divergences for any invariant vacuum state of the massive scalars. We derive a kinetic equation in global de Sitter space that follows from the Dyson-Schwinger equation of the Schwinger-Keldysh ...

Added: February 27, 2013

BOSSY M., Jabir J. M., Electronic Communications in Probability 2018 Vol. 23 P. 1-14

In this paper, we prove a particle approximation, in the sense of the propagation of chaos, of a Lagrangian stochastic model submitted to specular boundary condition and satisfying the mean no-permeability condition. ...

Added: June 7, 2018

Sergeev A., Васильев А. Ю., Russian Mathematical Surveys 2013 Vol. 68 No. 3 P. 435-502

Teichmüller theory is a ramified and rapidly developing area of mathematics which has multiple connections with other directions in the mathematical sciences and with their applications, first and foremost in mathematical physics. In this survey the main lines of development of this theory and its applications to string theory are presented in a historical context.
Bibliography: 128 titles. ...

Added: April 9, 2015

Пенза : ПГУ, 2015

В сборник трудов включены доклады юбилейного ХХ-го Международного симпозиума «Надежность и качество», проходившего с 25 по 31 мая 2015 г. в городе Пензе.
Рассмотрены актуальные проблемы теории и практики повышения надежности и качества; эффективности внедрения инновационных и информационных технологий в фундаментальных научных и прикладных исследованиях, образовательных и коммуникативных системах и средах, экономике и юриспруденции; методов и ...

Added: May 31, 2015

Belavin V., Geiko R., Journal of High Energy Physics 2017 Vol. 125 P. 1-13

We continue to investigate the dual description of the Virasoro conformal blocks arising in the framework of the classical limit of the AdS3/CFT2 correspondence. To give such an interpretation in previous studies, certain restrictions were necessary. Our goal here is to consider a more general situation available through the worldline approximation to the dual AdS gravity. ...

Added: August 31, 2017

Буров А.А., Герман А. Д., Косенко И. И., Космические исследования 2014 Т. 52 № 4 С. 307-312

The problem of planar oscillations of a pendulum with variable length suspended on the Moon’s surface is considered. It is assumed that the Earth and Moon (or, in the general case, a planet and its satellite, or an asteroid and a spacecraft) revolve around the common center of mass in unperturbed elliptical Keplerian orbits. We ...

Added: November 8, 2014

Gorsky A., Valba O. V., Journal of Complex Networks 2020 Vol. 8 No. 1 P. cnaa008

In this article, we show numerically the strong finite-size effects in exponential random graphs. Particularly, for the two-star model above the critical value of the chemical potential for triplets a ground state is a star-like graph with the finite set of hubs at network density p<0.5p<0.5 or as the single cluster at p>0.5p>0.5. We find that there exists ...

Added: August 28, 2020

Aseeva N., Gromov E., Onosova I. V. et al., JETP Letters 2016 Vol. 103 No. 10 P. 653-657

Evolution of solitons is addressed in the framework of a third-order nonlinear Schrödinger equation (NLSE), including nonlinear dispersion, third-order dispersion and a pseudo-stimulated-Raman-scattering (pseudo-SRS) term, i.e., a spatial-domain counterpart of the SRS term, which is well known as a part of the temporal domain NLSE in optics. In this context, it is induced by the ...

Added: June 28, 2016

Kurkina O. E., Kurkin A. A., Rouvinskaya E. et al., Письма в Журнал экспериментальной и теоретической физики 2012 Т. 95 № 2 С. 98-103

Nonlinear wave dynamics is discussed using the extended modified Korteweg–de Vries equation that includes the combination of the third- and fifth- order terms and is valid for waves in a three-layer fluid with so-called symmetric stratification. The derived equation has solutions in the form of solitary waves of various polarities. At small amplitudes, they are ...

Added: August 24, 2012