Showing papers by "Michael S. Fuhrer published in 1999"
TL;DR: In this article, the authors measured the electrical transport properties of single-walled carbon nanotubes (SWNTs) as a function of applied electric and magnetic fields and found that at low temperatures the resistance of SWNTs follows the Mott variable range hopping formula for hopping in three dimensions.
48 citations
TL;DR: In this paper, the carbon isotope effect with respect to the carbon superconducting single crystals of natural abundance has been measured with unprecedented accuracy and the measured isotope exponent is outside the error bars of all previous reported values.
Abstract: The sharp resistive transitions in superconducting single crystals of natural abundance and 99% ${}^{13}\mathrm{C}$-enriched ${\mathrm{Rb}}_{3}{\mathrm{C}}_{60}$ reveal the carbon isotope effect with unprecedented accuracy. The measured isotope exponent ${\ensuremath{\alpha}}_{\mathrm{C}}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.21\ifmmode\pm\else\textpm\fi{}0.012$ is outside the error bars of all previous reported values. Our precise value for ${\ensuremath{\alpha}}_{\mathrm{C}}$, combined with ${T}_{c}$, ${\ensuremath{\alpha}}_{\mathrm{Rb}}$, and an ab initio calculation of the frequency distribution of the electron-phonon coupling, allows a fully constrained determination of the coupling strength $\ensuremath{\lambda}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.9}_{\ensuremath{-}0.1}^{+0.15}$ and the Coulomb repulsion ${\ensuremath{\mu}}^{*}{\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0.22}_{\ensuremath{-}0.02}^{+0.03}$. These new measurements reveal a phonon-mediated superconductor with moderate coupling to a wide range of phonons centered near $\ensuremath{\sim}1400\mathrm{K}$.
37 citations