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The evolution of pairwise quantum correlations of Bell cat-states under amplitude damping is examined using the concept of quantum discord which goes beyond entanglement. A closed expression of the quantum discord is explicitly derived. We…

Quantum Physics · Physics 2015-06-11 M. Daoud , R. Ahl Laamara

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 propose an effective Hamiltonian approach to investigate decoherence of a quantum system in a non-Markovian reservoir, naturally imposing the complete positivity on the reduced dynamics of the system. The formalism is based on the notion…

Quantum Physics · Physics 2007-05-23 Jinhyoung Lee , Inbo Kim , Helen McAneney , M. S. Kim , Doyeol Ahn

We review recent studies on the measures of zero temperature quantum correlations namely, the quantum entanglement (concurrence) and discord present in the final state of a transverse XY spin chain following a quench through quantum…

Quantum Physics · Physics 2015-06-05 Tanay Nag , Amit Dutta , Ayoti Patra

We investigate decoherence-free evolution (DFE) of quantum discord (QD) for two initially-correlated qubits in two finite-temperature reservoirs using an exactly solvable model. We study QD dynamics of the two qubits coupled to two…

Quantum Physics · Physics 2011-02-15 Lan Xu , Ji-Bing Yuan , Qing-Shou Tan , Lan Zhou , Le-Man Kuang

We study the exact evolution of two non-interacting qubits, initially in a Bell state, in the presence of an environment, modeled by a kicked Ising spin chain. Dynamics of this model range from integrable to chaotic and we can handle…

Quantum Physics · Physics 2007-11-30 Carlos Pineda , Thomas H. Seligman

We investigate the freezing phenomenon of quantum discord occurring in phase damping noise processes. By relating the expression of the time variation of the discord to the convex function of relative entropy, we obtain the necessary and…

Quantum Physics · Physics 2015-03-13 Bo You , Li-Xiang Cen

In this paper, the dynamical behaviour of the geometric discord of a system consisting of a two-level atom interacting with a quantised radiation field described by the Jaynes-Cummings model has been studied. The evolution of the system has…

Quantum Physics · Physics 2015-06-19 Sina Hamedani Raja , Hamidreza Mohammadi , S. Javad Akhtarshenas

We show gapped critical environment could remarkably prevent an enhanced decay of decoherence factor and quantum correlations at the critical point, which is nontrivially different from the ones in a gapless critical environment (Quan,…

Quantum Physics · Physics 2015-08-03 R. Jafari , Alireza Akbari

We investigated the disentanglement dynamics of two-qubit system in Non-Markovian approach. We showed that only the couple strength with the environment near to or less than fine-structure constant 1/137, entanglement appear exponential…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Xiufeng Cao , Hang Zheng

The decoherence of two qubits, coupled with one-mode cavity separately, has been investigated exactly. The results show that, for the resonant case, the decoherence behavior of system is similar to Markovian case when the coupling strength…

Quantum Physics · Physics 2008-07-13 Fa-Qiang Wang , Wei-Ci Liu , Rui-Sheng Liang

We focus our attention on two-qubit mixed states as initial states, and apply the geometric measure of quantum discord to investigate quantum discord properties in the background of a Schwarzschild black hole under phase damping, phase flip…

Quantum Physics · Physics 2026-04-08 Yuxuan Xiong , Zhiling Pi , Tinggui Zhang , Xiaofen Huang

This work investigates the use of dynamical decoupling to shield quantum discord from errors introduced by the environment. Specifically, a two-qubits system interacting with independent baths of bosons is considered. The initial conditions…

Quantum Physics · Physics 2012-11-07 Felipe F. Fanchini , Emanuel F. de Lima , Leonardo K. Castelano

We study decoherence of two non-interacting qubits. The environment and its interaction with the qubits are modelled by random matrices. Decoherence, measured in terms of purity, is calculated in linear response approximation. Monte Carlo…

Quantum Physics · Physics 2007-11-22 C. Pineda , T. Gorin , T. H. Seligman

Cooperative effects in the loss (the amplitude damping) and decoherence (the phase damping) of the qubits (two-state quantum systems) due to the inevitable coupling to the same environment are investigated. It is found that the qubits…

Quantum Physics · Physics 2007-05-23 Lu-Ming Duan , Guang-Can Guo

We develop an analytical model for describing the dynamics of a donor-based charge quantum bit (qubit). As a result, the quantum decoherence of the qubit is analytically obtained and shown to reveal non-Markovian features: The decoherence…

Quantum Physics · Physics 2015-05-19 F Lastra , S Reyes , S Wallentowitz

We study the dynamics and decoherence of a system of two strongly driven qubits in a dissipative cavity. The two qubits have no direct interaction and are individually off-resonantly coupled to a single mode of quantized radiation. We…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 Marcin Dukalski , Ya. M. Blanter

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

Non-Markovian effects in quantum evolution appear when the system is strongly coupled to the environment and interacts with it for long periods of time. To include memory effects in the master equations, one usually incorporates time-local…

Quantum Physics · Physics 2020-11-24 Katarzyna Siudzińska , Dariusz Chruściński

This Letter deals with the time evolution of a qubit weakly coupled to a reservoir which has a symmetry broken state with long range order at finite temperatures. In particular, we model the ordered reservoir by a standard BCS…

Mesoscale and Nanoscale Physics · Physics 2013-04-16 Juliana Restrepo , S. Camalet , R. Chitra