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Among various definitions of quantum correlations, quantum discord has attracted considerable attention. To find analytical expression of quantum discord is an intractable task. In this paper, we discuss thoroughly the case of two-qubit…

Quantum Physics · Physics 2015-05-28 Mingjun Shi , Wei Yang , Fengjian Jiang , Jiangfeng Du

The von Neumann entropy at the output of a bosonic channel with thermal noise is analyzed. Coherent-state inputs are conjectured to minimize this output entropy. Physical and mathematical evidence in support of the conjecture is provided. A…

Quantum Physics · Physics 2009-11-10 Vittorio Giovannetti , Saikat Guha , Seth Lloyd , Lorenzo Maccone , Jeffrey H. Shapiro

The quantum discord is used as measure of quantum correlations for two families of multipartite coherent states. The first family interpolates between generalized GHZ states and generalized Werner states. The second one is an interpolation…

Quantum Physics · Physics 2012-11-01 M. Daoud , R. Ahl Laamara

Especially investigated in recent years, the Gaussian discord can be quantified by a distance between a given two-mode Gaussian state and the set of all the zero-discord two-mode Gaussian states. However, as this set consists only of…

Quantum Physics · Physics 2015-06-22 Paulina Marian , Tudor A. Marian

We consider the problem of time optimal control of a continuous bosonic quantum system subject to the action of a Markovian dissipation. In particular, we consider the case of a one mode Gaussian quantum system prepared in an arbitrary…

Quantum Physics · Physics 2014-12-01 Alberto Carlini , Andrea Mari , Vittorio Giovannetti

We discuss a generalization of the conditional entropy and one-way information deficit in quantum systems, based on general entropic forms. The formalism allows to consider simple entropic forms for which a closed evaluation of the…

Quantum Physics · Physics 2017-12-29 N. Canosa , M. Cerezo , N. Gigena , R. Rossignoli

We address the estimation of the loss parameter of a bosonic channel probed by arbitrary signals. Unlike the optimal Gaussian probes, which can attain the ultimate bound on precision asymptotically either for very small or very large…

Quantum Physics · Physics 2009-04-23 G. Adesso , F. Dell'Anno , S. De Siena , F. Illuminati , L. A. M. Souza

We explore experimentally the space of two-qubit quantum correlated mixed states, including frontier ones as defined by the use of quantum discord and von Neumann entropy. Our experimental setup is flexible enough to allow for the…

Quantum Physics · Physics 2011-08-31 Andrea Chiuri , Giuseppe Vallone , Mauro Paternostro , Paolo Mataloni

We present an algorithm for calculation of the Gaussian classical capacity of a quantum bosonic memory channel with additive Gaussian noise. The algorithm, restricted to Gaussian input states, is applicable to all channels with noise…

Quantum Physics · Physics 2015-03-17 Joachim Schäfer , Evgueni Karpov , Nicolas J. Cerf

We analyze the evolution of the Gaussian discord between two resonant harmonic oscillators coupled to a common environment. For this, we use the same tools we applied before to fully characterize the evolution of the entanglement in this…

Quantum Physics · Physics 2012-03-20 José Nahuel Freitas , Juan Pablo Paz

Non-Gaussian bosonic states are ubiquitous in interacting light--matter systems, many-body platforms, and relativistic quantum field settings, but their quantitative characterization is hindered by the infinite-dimensional Hilbert space and…

Quantum Physics · Physics 2026-03-17 Federico Centrone , Juan Pablo Paz , Augusto Roncaglia

We prove the multimode conditional quantum Entropy Power Inequality for bosonic quantum systems. This inequality determines the minimum conditional von Neumann entropy of the output of the most general linear mixing of bosonic quantum modes…

Quantum Physics · Physics 2025-07-08 Alessandro Falco , Giacomo De Palma

Quantum phase estimation based on Gaussian states plays a crucial role in many application fields. In this paper, we study the precision bound for the scheme using two-mode squeezed Gaussian states. The quantum Fisher information is…

Quantum Physics · Physics 2024-11-27 Jian-Dong Zhang , Chuang Li , Lili Hou , Shuai Wang

Quantum correlation often refers to correlations exhibited by two or more local subsystems under a suitable measurement. These correlations are beyond the framework of classical statistics and the associated classical probability…

Quantum Physics · Physics 2022-11-09 Biveen Shajilal , Elanor Huntington , Ping Koy Lam , Syed Assad

Bosonic quantum communication has extensively been analysed in the asymptotic setting, assuming infinite channel uses and vanishing communication errors. Comparatively fewer detailed analyses are available in the non-asymptotic setting,…

Quantum Physics · Physics 2025-03-06 Francesco Anna Mele , Giovanni Barbarino , Vittorio Giovannetti , Marco Fanizza

We provide experimental evidence of quantum features in bi-partite states classified as entirely classical according to a conventional criterion based on the Glauber P-function but possessing non-zero Gaussian quantum discord. Their quantum…

Quantum correlations between parts of a composite system most clearly reveal themselves through entanglement. Designing, maintaining, and controlling entangled systems is very demanding, which raises the stakes for understanding the…

Quantum Physics · Physics 2019-08-21 Matthew A. Hunt , Igor V. Lerner , Igor V. Yurkevich , Yuval Gefen

When a quantum system is divided into two local subsystems, measurements on the two subsystems can exhibit correlations beyond those possible in a classical joint probability distribution; these are partially explained by entanglement, and…

Quantum Physics · Physics 2019-06-17 Aaron Szasz

In quantum statistical mechanics, finite-temperature phase transitions are typically governed by classical field theories. In this context, the role of quantum correlations is unclear: recent contributions have shown how entanglement is…

Statistical Mechanics · Physics 2022-02-08 Poetri Sonya Tarabunga , Tiago Mendes-Santos , Fabrizio Illuminati , Marcello Dalmonte

We address the issue of reducing the resource required to compute information-theoretic quantum correlation measures like quantum discord and quantum work deficit in two qubits and higher dimensional systems. We show that determination of…

Quantum Physics · Physics 2015-12-18 Titas Chanda , Tamoghna Das , Debasis Sadhukhan , Amit Kumar Pal , Aditi Sen De , Ujjwal Sen