Search results for " ELECTRODYNAMICS"

Entangling N high-Q cavities

2004

A new conditional scheme for generating maximally entangled states of N spatially separated high-Q cavities is reported. The method is based on the passage of one atom only through all the N cavities. The unavoidable presence of fluctuations in the atom-cavity interaction times is carefully taken into account. The possibility of successfully implementing our proposal against cavity losses and atomic spontaneous decay is moreover discussed.

Studies of the hydrodynamic evolution of matter produced in fluctuations inp¯pcollisions and in ultrarelativistic nuclear collisions

1986

In this first paper of a series of two, we present a comprehensive study of the hydrodynamic evolution of matter produced in the central region of ultrarelativistic heavy-ion collisions and in high-multiplicity fluctuations of p-barp-italic collisions. We shall begin with a discussion of the limits of the applicability of a perfect-fluid hydrodynamic description of high-energy collisions. A simple bag-model equation of state is argued to have qualitative and semiquantitative features expected from lattice gauge theory and present theoretical understanding. We also discuss the boundary conditions for the perfect-fluid hydrodynamic equations, and what classes of simple events would correspond…

The leading disconnected contribution to the anomalous magnetic moment of the muon

2014

The hadronic vacuum polarization can be determined from the vector correlator in a mixed time-momentum representation. We explicitly calculate the disconnected contribution to the vector correlator, both in the $N_f = 2$ theory and with an additional quenched strange quark, using non-perturbatively $O(a)$-improved Wilson fermions. All-to-all propagators are computed using stochastic sources and a generalized hopping parameter expansion. Combining the result with the dominant connected contribution, we are able to estimate an upper bound for the systematic error that arises from neglecting the disconnected contribution in the determination of $(g-2)_\mu$.

Renormalization group analysis of thermal transport in the disordered Fermi liquid

2014

We present a detailed study of thermal transport in the disordered Fermi liquid with short-range interactions. At temperatures smaller than the impurity scattering rate, i.e., in the diffusive regime, thermal conductivity acquires non-analytic quantum corrections. When these quantum corrections become large at low temperatures, the calculation of thermal conductivity demands a theoretical approach that treats disorder and interactions on an equal footing. In this paper, we develop such an approach by merging Luttinger's idea of using gravitational potentials for the analysis of thermal phenomena with a renormalization group calculation based on the Keldysh nonlinear sigma model. The gravita…

Beyond linear response spectroscopy of ultracold fermi gases.

2005

We study RF-spectroscopy of ultracold Fermi gas by going beyond the linear response in the field-matter interaction. Higher order perturbation theory allows virtual processes and energy conservation beyond the single particle level. We formulate an effective higher order theory which agrees quantitatively with experiments on the pairing gap, and is consistent with the absence of the mean-field shift in the spin-flip experiment.

Band-selective third-harmonic generation in superconducting MgB2 : Possible evidence for the Higgs amplitude mode in the dirty limit

2021

General interpolation scheme for thermal fluctuations in superconductors

2006

We present a general interpolation theory for the phenomenological effects of thermal fluctuations in superconductors. Fluctuations are described by a simple gauge invariant extension of the gaussian effective potential for the Ginzburg-Landau static model. The approach is shown to be a genuine variational method, and to be stationary for infinitesimal gauge variations around the Landau gauge. Correlation and penetration lengths are shown to depart from the mean field behaviour in a more or less wide range of temperature below the critical regime, depending on the class of material considered. The method is quite general and yields a very good interpolation of the experimental data for very…

Relativistic simulations of superluminal sources

1997

Abstract We present numerical simulations of the radio emission from hydrodynamical relativistic jets. The quiescent-state jet emission consists of quasi-periodic knots of high emission, associated with internal recollimation shocks. Superluminal components can be reproduced by introducing a square-wave perturbation in the injection velocity of the jet. Strong interactions of the resulting moving shock and the standing recollimations result in a “drag” and increase in emission of the latter.

Multipole response of $^3$He clusters

1991

Ground state properties of normal 3He drops have been studied using either a correlated wave function in conjunction with a realistic potential of Aziz type1) or a mean-field description based on an effective potential 2,3). In general, an overall good agreement between both methods has been found. The second one has the advantage of being rather easily applicable to both static and dynamic calculations, although being less fundamental than the first one. In this work we are concerned with the description of the collective modes of normal 3He drops within the self-consistent Random-Phase Approximation (RPA), in which the same effective interaction is used to generate both the mean-field and…

Soliton-plasmon resonances as Maxwell nonlinear bound states

2012

We demonstrate that soliplasmons (soliton–plasmon bound states) appear naturally as eigenmodes of nonlinear Maxwell’s equations for a metal/Kerr interface. Conservative stability analysis is performed by means of finite element numerical modeling of the time-independent nonlinear Maxwell equations. Dynamical features are in agreement with the presented nonlinear oscillator model.