Session P39: Focus Session: Superconductivity-Theory and Computation (Mainly First Principles)

11:15 AM–2:03 PM, Wednesday, March 15, 2006
Baltimore Convention Center Room: 342

Sponsoring Units: DCOMP DCMP
Chair: Ole Andersen, Max Planck Institute

Abstract ID: BAPS.2006.MAR.P39.3

Abstract: P39.00003 : Superconductivity of Li, Al and K under pressure

12:03 PM–12:15 PM

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Author:

  Gianni Profeta
    (Univ. di L'Aquila (Italy))

C Franchini$^{\S}$, N. N. Lathiotakis$^{\dag}$, A. Floris$^{\dag\S}$, A. Sanna$^{\S}$, M. A. L. Marques$^{\dag}$, M.~L{\"u}ders$^{\ddag}$, S. Massidda$^{\S}$, E. K. U. Gross$^{\dag}$, A. Continenza$^{*}$.\\ $^{*}$ CASTI - INFM and Dip. Fis., Univ. di L'Aquila, I-67010 Coppito (L'Aquila) Italy; $^{\S}$ SLACS INFM and Dip. Fis., Univ. di Cagliari, I-09042 Monserrato (Ca), Italy; $^{\dag}$ Institut f{\"u}r Theoretische Physik, Freie Universit{\"a}t Berlin, Arnimallee 14, D-14195 Berlin, Germany; $^{\ddag}$ Daresbury Lab., Warrington WA4 4AD, United Kingdom.\\ Extreme pressure strongly affects the superconducting properties of ``simple'' metals, like Li, K and Al. Using the new ab-initio method of density functional theory of the superconducting state, we report investigations on the superconducting properties of dense Li, K and Al. Our results show an unprecedented agreement with experiments, assess the predictive power of the method over a wide range of densities and electron-phonon couplings, and provide predictions for K, where no experiments exist so far. For fcc K we predict a superconducting phase transition at 18 GPa, with a maximum critical temperature of about 2 K at 23 GPa, the pressure where the crossover between the fcc and the K $III$ structure experimentally occurs. We studied the effect of pressure on the electronic and vibrational properties of alkali, showing a progressive phonon softening near the K point of the Brillouin zone and a concomitant enhancement of the electron-phonon coupling constant $\lambda$.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2006.MAR.P39.3