4,314 research outputs found

    Localization-delocalization transition in one-dimensional electron systems with long-range correlated disorder

    Get PDF
    We investigate localization properties of electron eigenstates in one-dimensional (1d) systems with long-range correlated diagonal disorder. Numerical studies on the localization length ξ\xi of eigenstates demonstrate the existence of the localization-delocalization transition in 1d systems and elucidate non-trivial behavior of ξ\xi as a function of the disorder strength. The critical exponent ν\nu for localization length is extracted for various values of parameters characterizing the disorder, revealing that every ν\nu disobeys the Harris criterion ν>2/d\nu > 2/d.Comment: 6 pages, 6 figuers, to be published in Phys. Rev.

    Model for the unidirectional motion of a dynein molecule

    Full text link
    Cytoplasmic dyneins transport cellular organelles by moving on a microtubule filament. It has been found recently that depending on the applied force and the concentration of the adenosine triphosphate (ATP) molecules, dynein's step size varies. Based on these studies, we propose a simple model for dynein's unidirectional motion taking into account the variations in its step size. We study how the average velocity and the relative dispersion in the displacement vary with the applied load. The model is amenable to further extensions by inclusion of details associated with the structure and the processivity of the molecule.Comment: 10 pages, 5 figure

    Application of photodiodes to the detection of electromagnetic bursts

    Get PDF
    A new type of photodiode + scintillator (1 m2 x 1 cm) detector is developed to detect the large electro-magnetic burst under an EX-chamber. The threshold burst size is found to be 4.3 x 10 the 5 particles at the center of the scintillator. Therefore a gamma-ray family of 10 TeV is detectable by it, when it is set under 14 r.1. of iron. In addition, a very fast (2.4 nsec width) and very bright (correspond to 10 to the 6 particles) scintillation pulse has become avarable for this study

    Flexible control of the Peierls transition in metallic C60_{60} polymers

    Full text link
    The metal-semiconductor transition of peanut-shaped fullerene (C60_{60}) polymers is clarified by considering the electron-phonon coupling in the uneven structure of the polymers. We established a theory that accounts for the transition temperature TcT_c reported in a recent experiment and also suggests that TcT_c is considerably lowered by electron doping or prolonged irradiation during synthesis. The decrease in TcT_c is an appealing phenomenon with regard to realizing high-conductivity C60_{60}-based nanowires even at low temperatures.Comment: 3 pages, 3 figure

    Comparison of absolute intensity between EAS with gamma-families and general EAS at Mount Norikura

    Get PDF
    Gamma-families with total energy greater than 10 TeV, found in the EX chamber which was cooperated with the EAS array were combined with EAS triggered by big bursts. The absolute intensity of the size spectrum of these combined EAS was compared with that of general EAS obtained by AS trigger. The EAS with sizes greater than 2x1 million were always accompanied by gamma-families with sigma E sub gamma H 10 TeV, n sub gamma, H 2 and Emin=3 TeV, although the rate of EAS accompaning such gamma-families decreases rapidly as their sizes decrease

    Z decay into two massless gauge bosons in a magnetic field

    Get PDF
    An investigation of the processes Z to gluon-gluon and Z to photon-photon in a background magnetic field is presented. For homogeneous fields corrections to the charged fermion propagator can be calculated in leading orders of the magnetic field. This work examines the first order contributions of the corrected propagator to decays that are otherwise zero. Results of the decay rates for varying field strengths are included.Comment: 14 pages, 2 figures, needs RevTeX4; typos corrected, appendix added, references added, format changed to preprint mod
    corecore