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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

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

It is common knowledge that coupling to a heat bath, in general, tends to reduce the entanglement in a quantum system. In recent years, increasing interest has been devoted to the opposite situation where thermal or specifically tailored…

Quantum Physics · Physics 2014-06-11 Christopher Eltschka , Daniel Braun , Jens Siewert

We investigate the qubit geometric phase and its properties in dependence on the mechanism for decoherence of a qubit weakly coupled to its environment. We consider two sources of decoherence: dephasing coupling (without exchange of energy…

Quantum Physics · Physics 2011-06-01 J. Dajka , J. Luczka , P. Hanggi

The discovery of the intriguing phenomenon that certain kinds of quantum correlations remain impervious to noise up to a specific point in time and then suddenly decay, has generated immense recent interest. We exploit dynamical decoupling…

Quantum Physics · Physics 2018-02-14 Harpreet Singh , Arvind , Kavita Dorai

We consider two interacting electrons in a semiconductor quantum dot structure which consists of a small dot within a larger dot, and demonstrate a singlet-triplet filtering mechanism which involves spin-dependent resonances and can…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 G. Giavaras , J. H. Jefferson , M. Fearn , C. J. Lambert

We analyze the quantum entanglement at the equilibrium in a class of exactly solvable one-dimensional spin models at finite temperatures and identify a region where the quantum fluctuations determine the behavior of the system. We probe the…

Quantum Physics · Physics 2009-11-11 S. D. Hamieh , M. I. Katsnelson

We address a particular instance where open quantum systems may be used as quantum probes for an emergent property of a complex system, as the temperature of a thermal bath. The inherent fragility of the quantum probes against decoherence…

The quantum correlations between a qubit and its environment are described quantitatively in terms of interatomic distance. Specifically, considering a realistic system of two two-level atoms and taking into account the dipole-dipole…

Quantum Physics · Physics 2015-06-05 K. Berrada , F. F. Fanchini , S. Abdel-Khalek

We investigate the competition between pair entanglement of two spin qubits in double quantum dots attached to leads with various topologies and the separate entanglement of each spin with nearby electrodes. Universal behavior of…

Quantum Physics · Physics 2015-06-26 A. Ramsak , J. Mravlje , R. Zitko , J. Bonca

We demonstrate by an explicit model calculation that the decay of entanglement of two two-state systems (two qubits) is governed by the product of the factors that measure the degree of decoherence of each of the qubits, subject to…

Quantum Physics · Physics 2010-10-12 D. Tolkunov , V. Privman , P. K. Aravind

We derive an accurate molecular orbital based expression for the coherent time evolution of a two-electron wave function in a quantum dot molecule where the electrons interact with each other, with external time dependent electromagnetic…

Other Condensed Matter · Physics 2009-11-13 R. Nepstad , L. Sælen , J. P. Hansen

We provide an analytical investigation of the pairwise entanglement dynamics for a system, consisting an arbitrary number of qubits dissipating into a common and non-Markovian environment for both weak and strong coupling regimes. In the…

Quantum Physics · Physics 2016-03-23 Alireza Nourmandipour , Mohammad Kazem Tavassoly , Morteza Rafiee

We study the reduced dynamics of a spin (qubit) coupled to a spin-boson environment in the case of pure dephasing. We derive formal exact expressions which can be cast in terms of exact integro-differential master equations. We present…

Statistical Mechanics · Physics 2009-11-10 E. Paladino , M. Sassetti , G. Falci

For the case of phase damping (pure decoherence) we investigate the extent to which environmental traits are imprinted on an open quantum system. The dynamics is described using the quantum channel approach. We study what the knowledge of…

Quantum Physics · Physics 2015-05-20 Julius Helm , Walter T. Strunz , Stephan Rietzler , Lars Erik Würflinger

An experimental scheme is suggested that permits a direct measure of entanglement in a two-qubit cavity system. It is realized in the cavity-QED technology utilizing atoms as flying qubits. With this scheme we generate two different…

Quantum Physics · Physics 2011-07-04 Smail Bougouffa

Few studies explored the dynamics of non-classical correlations besides entanglement in open multipartite quantum systems. Here, we address the time-evolution of quantum discord and entanglement in a model of three non-interacting qubits…

Quantum Physics · Physics 2013-04-11 Fabrizio Buscemi , Paolo Bordone

We analyze the decoherence induced on a single qubit by the interaction with a two-level boson system with critical internal dynamics. We explore how the decoherence process is affected by the presence of quantum phase transitions in the…

Quantum Physics · Physics 2015-05-14 A. Relano , J. M. Arias , J. Dukelsky , J. E. Garcia-Ramos , P. Perez-Fernandez

We extract the phase coherence of a qubit defined by singlet and triplet electronic states in a gated GaAs triple quantum dot, measuring on timescales much shorter than the decorrelation time of the environmental noise. In this non-ergodic…

Mesoscale and Nanoscale Physics · Physics 2016-01-28 M. R. Delbecq , T. Nakajima , P. Stano , T. Otsuka , S. Amaha , J. Yoneda , K. Takeda , G. Allison , A. Ludwig , A. D. Wieck , S. Tarucha

We propose and experimentally verify a cooling limit for a quantum channel going through an incoherent environment. The environment consists of a large number of independent non-interacting and non-interfering elementary quantum systems -…

Quantum Physics · Physics 2015-11-25 Ivo Straka , Martina Miková , Michal Mičuda , Miloslav Dušek , Miroslav Ježek , Radim Filip