Initial correlations effects on decoherence at zero temperature

Bellomo, Bruno; Petruccione, Francesco

doi:10.1088/0305-4470/38/47/010

Cited by 7 publications

(13 citation statements)

References 39 publications

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“…Moreover, the initial correlations can be important for considering the ultrafast relaxation and non-Markovian processes and also for describing the decoherence phenomenon (see, e.g., [12]). To take the initial correlations into account, a method (based on the conventional time-independent projection operator technique) that allows converting the linear inhomogeneous time-convolution GME (TC-GME) [8]- [10] and time-convolutionless GME (TCL-GME) [13], [14] into the homogeneous form exactly was recently proposed [15], [16].…”

Section: Introductionmentioning

confidence: 99%

Nonlinear generalized master equations and accounting for initial correlations

Los

2009

Theor Math Phys

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We develop a new method based on using a time-dependent operator (generally not a projection operator) converting a distribution function (statistical operator) of a total system into the relevant form that allows deriving new exact nonlinear generalized master equations (GMEs). The derived inhomogeneous nonlinear GME is a generalization of the linear Nakajima-Zwanzig GME and can be viewed as an alternative to the BBGKY chain. It is suitable for obtaining both nonlinear and linear evolution equations. As in the conventional linear GME, there is an inhomogeneous term comprising all multiparticle initial correlations. To include the initial correlations into consideration, we convert the obtained inhomogeneous nonlinear GME into the homogenous form by the previously suggested method. We use no conventional approximation like the random phase approximation (RPA) or the Bogoliubov principle of weakening of initial correlations. The obtained exact homogeneous nonlinear GME describes all evolution stages of the (sub)system of interest and treats initial correlations on an equal footing with collisions via the modified memory kernel. As an application, we obtain a new homogeneous nonlinear equation retaining initial correlations for a one-particle distribution function of the spatially inhomogeneous nonideal gas of classical particles. In contrast to existing approaches, this equation holds for all time scales and takes the influence of pair collisions and initial correlations on the dissipative and nondissipative characteristics of the system into account consistently with the adopted approximation (linear in the gas density). We show that on the kinetic time scale, the time-reversible terms resulting from the initial correlations vanish (if the particle dynamics are endowed with the mixing property) and this equation can be converted into the Vlasov-Landau and Boltzmann equations without any additional commonly used approximations. The entire process of transition can thus be followed from the initial reversible stage of the evolution to the irreversible kinetic stage.

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Section: Introductionmentioning

confidence: 99%

Nonlinear generalized master equations and accounting for initial correlations

Los

2009

Theor Math Phys

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“…Previously it has been shown that decoherence evolution is influenced by the presence of initial partial correlation [31,32,33,34]. It appears of interest to analyze in which way the results obtained in this paper are modified in the more realistic case in which partial correlations between the system and the environment are present since the beginning.…”

Section: Discussionmentioning

confidence: 86%

Loss of coherence and dressing in QED

Bellomo

Petruccione

2006

Phys. Rev. A

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The dynamics of a free charged particle, initially described by a coherent wave packet, interacting with an environment, i.e. the electromagnetic field characterized by a temperature T , is studied. Using the dipole approximation the exact expressions for the evolution of the reduced density matrix both in momentum and configuration space and the vacuum and the thermal contribution to decoherence, are obtained. The time behaviour of the coherence lengths in the two representations are given. Through the analysis of the dynamic of the field structure associated to the particle the vacuum contribution is shown to be linked to the birth of correlations between the single momentum components of the particle wave packet and the virtual photons of the dressing cloud.

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“…However decoherence can be influenced by the presence of initial correlations [17,18], so if an interaction is always present, as for the case of charged particles interacting with vacuum fluctuations, a more realistic initial condition should consist in treating the particle and the field as initially correlated [19].…”

Section: Discussionmentioning

confidence: 99%

Spatial Decoherence in QED

Bellomo

Petruccione

2006

Open Syst. Inf. Dyn.

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We consider the dynamics of a charged free particle, initially described by a coherent wave packet, interacting with an electromagnetic field characterized by the temperature T , considered as the environment. We have used dipole approximation neglecting the potential vector quadratic term in the minimal coupling Hamiltonian. This leads to the loss of coherence in the momentum representation, described by the decay of the off diagonal elements of the particle reduced density matrix, while the populations remain constant. Here we extend the analysis to the coordinate representation. We compute the particle reduced density matrix in this basis, analyzing in particular the mixing of various effects, such as free spreading, vacuum dressing and vacuum and thermal decoherence, in the wave packet width and coherence length evolution.

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Initial correlations effects on decoherence at zero temperature

Cited by 7 publications

References 39 publications

Nonlinear generalized master equations and accounting for initial correlations

Nonlinear generalized master equations and accounting for initial correlations

Loss of coherence and dressing in QED

Spatial Decoherence in QED

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