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Related papers: Creating quantum discord through local generalized…

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The non-Markovian decoherence of quantum and classical correlations is analytically obtained when two qubits are asymmetrically subjected to the bit flip channel and phase flip channel. For one class of initial mixed states, quantum…

Quantum Physics · Physics 2012-08-09 Xiang Hao , Tao Pan , Jinqiao Sha

We use quantum discord to characterize the correlations present in the quantum computational model DQC1, introduced by Knill and Laflamme [Phys. Rev. Lett. 81, 5672 (1998)]. The model involves a collection of qubits in the completely mixed…

Quantum Physics · Physics 2009-11-13 Animesh Datta , Anil Shaji , Carlton M. Caves

We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only…

Quantum Physics · Physics 2015-03-13 F. F. Fanchini , T. Werlang , C. A. Brasil , L. G. E. Arruda , A. O. Caldeira

We experimentally show how classical correlations can be turned into quantum entanglement, via the presence of non-unital local noise and the action of a CNOT gate. We first implement a simple two-qubit protocol in which entanglement…

We have found that for a wide range of two-qubit Hamiltonians the canonical-ensemble thermal state is entangled in two distinct temperature regions. In most cases the ground state is entangled; however we have also found an example where…

Quantum Physics · Physics 2007-05-23 Dominic W. Berry , Mark R. Dowling

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 study information transmission over a fully correlated amplitude damping channel acting on two qubits. We derive the single-shot classical channel capacity and show that entanglement is needed to achieve the channel best performance. We…

Quantum Physics · Physics 2013-11-01 A. D'Arrigo , G. Benenti , G. Falci , C. Macchiavello

We study the peculiar dynamics of two qubits quantum discord with a sudden change in behavior. It is widely agreed in the literature nowadays that environment induce sudden change behavior of quantum discord. We explore the sudden change…

Quantum Physics · Physics 2023-01-19 Mei Bai , Xiang-Yu Qin , Xue-Qun Yan

Using an exactly solvable pure dephasing model, we show how entanglement between qubits can be generated via the interaction with a common environment and concurrent application of suitable control pulses. The control pulses are able to…

Quantum Physics · Physics 2022-12-09 Muhammad Abdullah Mutahar , Adam Zaman Chaudhry

Non-classical correlations play a crucial role in the development of quantum information science. The recent discovery that non-classical correlations can be present even in separable (unentangled) states has broadened this scenario. This…

We analyze the quantum discord Q throughout the low-temperature phase diagram of the quantum XY model in transverse field. We first focus on the T=0 order-disorder quantum phase transition both in the symmetric ground state and in the…

Statistical Mechanics · Physics 2012-09-24 Bruno Tomasello , Davide Rossini , Alioscia Hamma , Luigi Amico

Multiple photonic degrees of freedom can be explored to generate high-dimensional quantum states; commonly referred to as `qudits'. Qudits offer several advantages for quantum communications, including higher information capacity, noise…

Quantum Physics · Physics 2023-03-21 Indrakshi Dey , Nicola Marchetti

It is shown that quantum coherence is conserved in a principal system in the case that the system is coupled to a fast dissipating environment [arXiv:0709.0562]. The phenomenon is called the quantum wipe effect. Here, this effect is…

Quantum Physics · Physics 2008-08-06 Robabeh Rahimi , Akira SaiToh , Mikio Nakahara

Recently, it was realized that quantum discord can be seen as the minimal amount of correlations which are lost when some local quantum operations are performed. Based on this formulation of quantum discord, we provide a systematical…

Quantum Physics · Physics 2011-12-21 Małgorzata Okrasa , Zbigniew Walczak

We address the issue of the discrimination between two-qubit amplitude damping channels by exploring several strategies. For the single-shot, we show that the excited state does not always give the optimal input, and that side entanglement…

Quantum Physics · Physics 2021-05-11 Milajiguli Rexiti , Stefano Mancini

It has been proven that the quantum discord is a more general tool to capture non-classical correlation than quantum entanglement, because there is a non-zero quantum discord in several mixed states that could not be measured by quantum…

Quantum Physics · Physics 2015-03-20 N. Doustimotlagh

It is known from the analysis of the density matrix for bipartite systems that the quantum discord (as a measure of quantum correlations) depends on the particular subsystem chosen for the projective measurements. We study asymmetry of the…

Quantum Physics · Physics 2015-05-27 E. B. Fel'dman , A. I. Zenchuk

We study the dynamics of quantum correlations for two non interacting qubits initially prepared in a maximally entangled state and then coupled with an external environment characterized by a noise spectrum of the form 1/f^{\alpha}. The…

Quantum Physics · Physics 2013-12-24 Claudia Benedetti , Matteo G. A. Paris , Fabrizio Buscemi , Paolo Bordone

In the framework of the theory of open systems based on completely positive quantum dynamical semigroups, we give a description of continuous variable quantum entanglement and quantum discord for a system consisting of two non-interacting…

Quantum Physics · Physics 2015-06-12 Aurelian Isar

We introduce a new class of quantum channels, the Generalized Multilevel Amplitude Damping (GMAD) channels, to model noise and decoherence effects in a qudit coupled to a thermal environment. The degradation of energetic resources under…

Quantum Physics · Physics 2026-05-27 Vito Vetrano , Vittorio Giovannetti , Vasco Cavina