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Related papers: Pure Phase Decoherence in a Ring Geometry

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We report on the immersion of a spin-qubit encoded in a single trapped ion into a spin-polarized neutral atom environment, which possesses both continuous (motional) and discrete (spin) degrees of freedom. The environment offers the…

Quantum Physics · Physics 2014-07-24 L. Ratschbacher , C. Sias , L. Carcagni , J. M. Silver , C. Zipkes , M. Köhl

We study pure phase damping of two qubits due to fluctuating fields. As frequently employed, decoherence is thus described in terms of random unitary (RU) dynamics, i.e., a convex mixture of unitary transformations. Based on a separation of…

Quantum Physics · Physics 2010-12-22 Julius Helm , Walter T. Strunz

The amplitude of the Bohm-Aharonov oscillations of a particle moving around a ring threaded by a magnetic flux and coupled to different dissipative environments is studied. The decay of the oscillations when increasing the radius of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 F. Guinea

The time evolution of a qubit, consisting of two single-level quantum dots, is studied in the presence of telegraph noise. The dots are connected by two tunneling paths, with an Aharonov-Bohm flux enclosed between them. Under special…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 A. Aharony , S. Gurvitz , O. Entin-Wohlman , S. Dattagupta

The dynamics and decoherence of an electronic spin-1/2 qubit coupled to a bath of nuclear spins via hyperfine interactions in a quantum dot is studied. We show how exact results from the integrable solution can be used to understand the…

Strongly Correlated Electrons · Physics 2010-10-22 Michael Bortz , Sebastian Eggert , Christian Schneider , Robert Stubner , Joachim Stolze

We calculate the geometric phase of a spin-1/2 particle coupled to an external environment comprising N spin-1/2 particle in the framework of open quantum systems. We analyze the decoherence factor and the deviation of the geometric phase…

Quantum Physics · Physics 2009-11-13 Paula I. Villar

We numerically investigate decoherence of a two-spin system (central system) by a bath of many spins 1/2. By carefully adjusting parameters, the dynamical regime of the bath has been varied from quantum chaos to regular, while all other…

Quantum Physics · Physics 2009-11-10 J. Lages , V. V. Dobrovitski , B. N. Harmon

Phase effects on the conductance of a double-dot system in a ring structure threaded by a magnetic flux are studied. The Aharonov-Bohm effect combined with the dot many-body charging effects determine the phases of the currents going…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 V. M. Apel , Maria A. Davidovich , G. Chiappe , E. V. Anda

We consider classical hard-core particles moving on two parallel chains in the same direction. An interaction between the channels is included via the hopping rates. For a ring, the stationary state has a product form. For the case of…

Statistical Mechanics · Physics 2011-07-13 Vladislav Popkov , Ingo Peschel

We investigate decoherence due to pure dephasing of a localized spin qubit interacting with a nuclear spin bath. Although in the limit of a very large magnetic field the only decoherence mechanism is spectral diffusion due to dipolar…

Mesoscale and Nanoscale Physics · Physics 2009-06-18 L. Cywinski , W. M. Witzel , S. Das Sarma

We study the decoherence of a spin in a quantum dot due to its hyperfine coupling to a randomly fluctuating bath of nuclear spins. The system is modelled by the central spin model with the spin bath initially being at infinite temperature.…

Mesoscale and Nanoscale Physics · Physics 2013-09-02 Alexandre Faribault , Dirk Schuricht

The dynamics of a spin-1/2 particle coupled to a nuclear spin bath through an isotropic Heisenberg interaction is studied, as a model for the spin decoherence in quantum dots. The time-dependent polarization of the central spin is…

Quantum Physics · Physics 2007-06-28 D. D. Bhaktavatsala Rao , V. Ravishankar , V. Subrahmanyam

The quantum average energy decay and the purity decay are studied for a system particle as a function of the number of constituents of a discrete bath model. The system particle is subjected to two distinct physical situations: the harmonic…

Quantum Physics · Physics 2011-11-02 M. D. Galiceanu , M. W. Beims , W. Strunz

As a continuation of our previous work, we derive the optimal flux phase which minimizes the ground state energy in the one-dimensional many particle systems, when the number of particles is odd in the absence of on-site interaction and…

Mathematical Physics · Physics 2009-11-10 Fumihiko Nakano

We systematically investigate the universal spin decoherence dynamics of a localized electron in an arbitrary nuclear spin bath, which can be even far away from equilibrium due to the weak nuclear-lattice interaction. We show that the…

Mesoscale and Nanoscale Physics · Physics 2008-06-27 Yi-Ya Tian , Pochung Chen , Daw-Wei Wang

The dynamics of a dimer coupled to two different environments each in a spin star configuration under the influence of decoherence is studied. The exact analytical expression for the transition probability in the dimer system is obtained…

Quantum Physics · Physics 2014-01-15 I. Sinayskiy , A. Marais , F. Petruccione , A. Ekert

We review different attempts to show the decoherence process in double-slit-like experiments both for charged particles (electrons) and neutral particles with permanent dipole moments. Interference is studied when electrons or atomic…

Quantum Physics · Physics 2009-11-11 Fernando C. Lombardo , Paula I. Villar

We consider a particle coupled to a dissipative environment and derive a perturbative formula for the dephasing rate based on the purity of the reduced probability matrix. We apply this formula to the problem of a particle on a ring, that…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Doron Cohen , Baruch Horovitz

Vacuum fluctuations are a source of irreversibility and decoherence. We investigate the persistent current and its fluctuations in a ring with an in-line quantum dot with an Aharonov-Bohm flux through the hole of the ring. The Coulomb…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Markus Buttiker

We study the spatial decoherence dynamics for the relative position of two atoms in a singlemode ring cavity. We find that the spatial decoherence of the two atoms depends strongly on their relative position. Taking into account the spatial…

Quantum Physics · Physics 2015-05-20 Li Zheng , Chui-Ping Yang , Franco Nori
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