12 research outputs found

    Fractal superconductivity near localization threshold

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    We develop a semi-quantitative theory of electron pairing and resulting superconductivity in bulk "poor conductors" in which Fermi energy EFE_F is located in the region of localized states not so far from the Anderson mobility edge EcE_c. We review the existing theories and experimental data and argue that a large class of disordered films is described by this model. Our theoretical analysis is based on the analytical treatment of pairing correlations, described in the basis of the exact single-particle eigenstates of the 3D Anderson model, which we combine with numerical data on eigenfunction correlations. Fractal nature of critical wavefunction's correlations is shown to be crucial for the physics of these systems. We identify three distinct phases: 'critical' superconductive state formed at EF=EcE_F=E_c, superconducting state with a strong pseudogap, realized due to pairing of weakly localized electrons and insulating state realized at EFE_F still deeper inside localized band. The 'critical' superconducting phase is characterized by the enhancement of the transition temperature with respect to BCS result, by the inhomogeneous spatial distribution of superconductive order parameter and local density of states. The major new feature of the pseudo-gaped state is the presence of two independent energy scales: superconducting gap Δ\Delta, that is due to many-body correlations and a new "pseudogap" energy scale ΔP\Delta_P which characterizes typical binding energy of localized electron pairs and leads to the insulating behavior of the resistivity as a function of temperature above superconductive TcT_c. Two gap nature of the "pseudo-gaped superconductor" is shown to lead to a number of unusual physical properties.Comment: 110 pages, 39 figures. The revised version corrects a number of typos, adds references and discussion of recent result

    Examination of the static pressure of the plasma arc

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    20.00; Translated from Russian (Problemy Spetsial'noi Elektrometallurgii 1990 v. 6(1) p. 86-88)Available from British Library Document Supply Centre- DSC:9023.19(VR-Trans--4550)T / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

    CMS Physics Technical Design Report: Addendum on High Density QCD with Heavy Ions

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    This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies sNN=5.5TeV\sqrt{s_{NN}}= 5.5\,{\rm TeV} , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction \u2014 Quantum Chromodynamics (QCD) \u2014 in extreme conditions of temperature, density and parton momentum fraction (low- x ). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low p T inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high p T hadrons which yield "tomographic" information of the hottest and densest phases of the reaction
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