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The conditions are established for nullity of quantum discord for mixed states of a general two-qubit system whose dynamical behaviour is given by an X-state form density matrix. It is found that quantum discord can vanish at a finite time…

Quantum Physics · Physics 2011-01-27 Gao-xiang Li , Zhen Yi , Zbigniew Ficek

In this paper the correlations dynamics of two atoms in the case of a micromaser-type system is investigated. Our results predict certain quasi-periodic collapse and revival phenomena for quantum discord and entanglement when the field is…

Quantum Physics · Physics 2014-10-02 Xue-Qun Yan , Bo-Ying Zhang

We study the dynamics of quantum correlations of two coupled double quantum dots containing two excess electrons. The dissipation is included through the contact with an oscillator bath. We solve the Redfield master equation in order to…

Quantum Physics · Physics 2010-07-08 F. F. Fanchini , L. K. Castelano , A. O. Caldeira

We study the computational complexity of quantum discord (a measure of quantum correlation beyond entanglement), and prove that computing quantum discord is NP-complete. Therefore, quantum discord is computationally intractable: the running…

Quantum Physics · Physics 2014-03-31 Yichen Huang

We have proposed a scheme of the generation and preservation of two-qubit steady state quantum correlations through quantum channels where successive uses of the channels are correlated. Different types of noisy channels with memory, such…

Quantum Physics · Physics 2016-04-15 You-neng Guo , Mao-fa Fang , Guo-you Wang , Ke Zeng

We study nonclassical correlations in propagating two-mode squeezed microwave states in the presence of noise. We focus on two different types of correlations, namely, quantum entanglement and quantum discord. Quantum discord has various…

We investigated the dissipative dynamics of quantum discord for correlated qubits under Markovian environments. The basic idea in the present scheme is that quantum discord is more general, and possibly more robust and fundamental, than…

Quantum Physics · Physics 2015-06-04 M. Mahdian , R. Yousefjani , S. Salimi

The benefits of entanglement can outlast entanglement itself. In quantum illumination, entanglement is employed to better detect reflecting objects in environments so noisy that all entanglement is destroyed. Here, we show that quantum…

Quantum Physics · Physics 2016-04-20 Christian Weedbrook , Stefano Pirandola , Jayne Thompson , Vlatko Vedral , Mile Gu

We generate different orders of quantum coherence in a three-qubit NMR system and study their dynamics in the presence of inherent noise. Robust dynamical decoupling (DD) sequences are applied to preserve the different coherence orders.…

Quantum Physics · Physics 2024-11-12 Akanksha Gautam , Kavita Dorai , Arvind

The non-Markovian dynamics of quantum entanglement is studied by the Shabani-Lidar master equation when one of entangled quantum systems is coupled to a local reservoir with memory effects. The completely positive reduced dynamical map can…

Quantum Physics · Physics 2015-06-11 Xiang Hao , Jinqiao Sha , Jian Sun , Shiqun Zhu

We analyse under which dynamical conditions the coherence of an open quantum system is totally unaffected by noise. For a single qubit, specific measures of coherence are found to freeze under different conditions, with no general agreement…

Quantum Physics · Physics 2015-05-28 Thomas R. Bromley , Marco Cianciaruso , Gerardo Adesso

We investigate the amount of entanglement and quantum discord extractable from a two mode squeezed state as considered from the viewpoint of two observers, Alice (inertial) and Rob (accelerated). We find that using localized modes produces…

Quantum Physics · Physics 2013-03-27 Jason Doukas , Eric G. Brown , Andrzej Dragan , Robert Mann

The dissipative dynamics of two interacting qubits coupled to independent reservoirs at nonzero temperatures is investigated, paying special attention to the entanglement evolution. The counter-rotating terms in the qubit-qubit interaction…

Quantum Physics · Physics 2015-05-13 M. Scala , R. Migliore , A. Messina , L. L. Sanchez-Soto

We study the relative strength of classical and quantum correlations, as measured by discord, for two-qubit states. Quantum correlations appear only in the presence of classical correlations, while the reverse is not always true. We…

Quantum Physics · Physics 2011-01-17 Fernando Galve , Gian Luca Giorgi , Roberta Zambrini

We investigate the quantum correlations in an axially symmetric hybrid qubit-qutrit system subjected to different noisy environments. We first introduce a physical model and analyze its Hamiltonian structure, emphasizing the role of hybrid…

Quantum Physics · Physics 2026-01-01 M. Abdellaoui , N. -E. Abouelkhir , A. Slaoui , R. Ahl Laamara , S. Haddadi

We study the dynamics of two identical atoms resonantly coupled to a single-mode cavity under practical feedback control, and focus on the detection inefficiency. The entanglement is induced to vanish in finite time by the inefficiency of…

Quantum Physics · Physics 2015-05-27 Yang Li , Bin Luo , Hong Guo

Quantum systems unfold diversified correlations which have no classical counterparts. These quantum correlations have various different facets. Quantum entanglement, as the most well known measure of quantum correlations, plays essential…

We investigate the dynamics of quantum discord and entanglement for a class of mixed qubit-qutrit states assuming that only the qutrit is under the action of a dephasing channel. We demonstrate that even though the entanglement in the…

Quantum Physics · Physics 2013-04-02 G. Karpat , Z. Gedik

Entanglement behavior for different classes of two qubit systems passing through a generalized amplitude damping channel is discussed. The phenomena of sudden single, double changes and the sudden death of entanglement are reported for…

Quantum Physics · Physics 2015-06-18 Nasser Metwally

Measurements of Quantum Systems disturb their states. To quantify this non-classical characteristic, Zurek and Ollivier introduced the quantum discord, a quantum correlation which can be nonzero even when entanglement in the system is zero.…

Quantum Physics · Physics 2010-07-13 Asma Al-Qasimi , Daniel F. V. James