43,705 research outputs found

    Electron localization near Mott transition in organic superconductor κ\kappa-(BEDT-TTF)2_{2}Cu[N(CN)2]_{2}]Br

    Full text link
    The effect of disorder on the electronic properties near the Mott transition is studied in an organic superconductor κ\kappa-(BEDT-TTF)2_{2}Cu[N(CN)2_{2}]Br, which is systematically irradiated by X-ray. We observe that X-ray irradiation causes Anderson-type electron localization due to molecular disorder. The resistivity at low temperatures demonstrates variable range hopping conduction with Coulomb interaction. The experimental results show clearly that the electron localization by disorder is enhanced by the Coulomb interaction near the Mott transition.Comment: 5 pages, 4 figure

    Bogoliubov Theory and Lee-Huang-Yang Corrections in Spin-1 and Spin-2 Bose-Einstein Condensates in the Presence of the Quadratic Zeeman Effect

    Full text link
    We develop Bogoliubov theory of spin-1 and spin-2 Bose-Einstein condensates (BECs) in the presence of a quadratic Zeeman effect, and derive the Lee-Huang-Yang (LHY) corrections to the ground-state energy, sound velocity, and quantum depletion. We investigate all the phases of spin-1 and spin-2 BECs that can be realized experimentally. We also examine the stability of each phase against quantum fluctuations and the quadratic Zeeman effect. Furthermore, we discuss a relationship between the number of symmetry generators that are spontaneously broken and that of Nambu-Goldstone (NG) modes. It is found that in the spin-2 nematic phase there are special Bogoliubov modes that have gapless linear dispersion relations but do not belong to the NG modes.Comment: v3: 62 pages, 18 figure

    Static Trace-Based Deadlock Analysis for Synchronous Mini-Go

    Full text link
    We consider the problem of static deadlock detection for programs in the Go programming language which make use of synchronous channel communications. In our analysis, regular expressions extended with a fork operator capture the communication behavior of a program. Starting from a simple criterion that characterizes traces of deadlock-free programs, we develop automata-based methods to check for deadlock-freedom. The approach is implemented and evaluated with a series of examples

    Constant mean curvature surfaces of any positive genus

    Full text link
    We show the existence of several new families of non-compact constant mean curvature surfaces: (i) singly-punctured surfaces of arbitrary genus g1g \geq 1, (ii) doubly-punctured tori, and (iii) doubly periodic surfaces with Delaunay ends.Comment: 14 pages, 10 figure

    Magnetic and Electronic Phase Diagram and Superconductivity in the Organic Superconductors k-(BEDT-TTF)2X

    Get PDF
    The magnetic susceptibility of the organic superconductors κ\kappa-(h8 or d8-ET)2_{2}XX, X=X = Cu(NCS)2_{2} and Cu[N(CN)2_{2}]Br has been studied. A metallic phase below T=T^{*} = 37 \sim 38 K for X=X = Cu[N(CN)2_{2}]Br and 46 \sim 50 K for X=X = Cu(NCS)2_{2} has an anisotropic temperature dependence of the susceptibility and the charge transport. Partial charge-density-wave or charge fluctuation is expected to coexist with the metallic phase instead of the large antiferromagnetic fluctuation above TT^{*}. The phase diagram and the superconductivity of κ\kappa-(ET)2_{2}XX are discussed in connection with this phase.Comment: 5 pages, 4figures, REVTeX, references are corrected, accepted for pubication in Phys. Rev.
    corecore