Alain Audouard

A high-resistivity phase induced by swift heavy-ion irradiation of Bi: a probe for thermal spike damage?

Pure bismuth samples were irradiated at 20 K with swift heavy ions from 18O to 238U in the GeV range. The rate of the induced damage was deduced from in situ electrical resistance measurements. Above a threshold in the electronic stopping power Se equal to 24 keV nm-1, the damage is due to electronic slowing down. Above 30 keV nm-1, the electronic slowing down is efficient enough to induce latent tracks attributed to the appearance of a high-resistivity phase. The induced latent tracks radii can be up to 21.9 nm for Se=51 keV nm-1 which is the largest value reported so far for non-radiolytic materials. The evolution with Se of the latent tracks radii is calculated on the basis of the thermal spike model, assuming a realistic value for the electron-phonon coupling constant. A rather good agreement is obtained which supports the idea that the thermal spike could be operative in the observed radiation damage.

de Haas-van Alphen Oscillations in the Underdoped High-Temperature Superconductor YBa2Cu3O6.5

Cyril Jaudet, David Vignolles, ∗ Alain Audouard, Julien Levallois, D. LeBoeuf, Nicolas Doiron-Leyraud, B. Vignolle, M. Nardone, A. Zitouni, Ruixing Liang, 4 D.A. Bonn, 4 W.N. Hardy, 4 Louis Taillefer, 4 and Cyril Proust † Laboratoire National des Champs Magnétiques Pulsés (CNRS-UPS-INSA), Toulouse, France Département de physique & RQMP, Université de Sherbrooke, Sherbrooke, Canada Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada Canadian Institute for Advanced Research, Toronto, Canada (Dated: May 13, 2008)

Multiple quantum oscillations in the de Haas-van Alphen spectra of the underdoped high-temperature superconductor YBa2Cu3O6.5.

By improving the experimental conditions and extensive data accumulation, we have achieved very high precision in the measurements of the de Haas-van Alphen effect in the underdoped high-temperature superconductor YBa2Cu3O6.5. We find that the main oscillation, so far believed to be single frequency, is composed of three closely spaced frequencies. We attribute this to bilayer splitting and warping of a single quasi-2D Fermi surface, indicating that c axis coherence is restored at low temperature in underdoped cuprates. Our results do not support the existence of a larger frequency of the order of 1650 T reported recently in the same compound [S. E. Sebastian, Nature (London) 454, 200 (2008)].

Transport properties and giant Shubnikov-de Haas oscillations in the first organic conductor with metal complex anion containing selenocyanate ligand, (ET)2 T1Hg(SeCN)4

Abstract Temperature dependence of the resistivity in various crystallographic directions and high pulsed field magnetoresistance of organic metal α-(ET) 2 TlHg(SeCN) 4 have been studied at temperatures down to 80 mK. Giant Shubnikov-de Haas oscillations, which are attributed to the two-dimensional nature of the cylindrical Fermi surface with a very small warping along the direction of the lowest conductivity have been observed. Four harmonics of the fast oscillations with fundamental frequency F 0 = 653 ± 3 T and slow frequency oscillations with F s = 38 ± 5 T have been revealed.

Quantum oscillations and upper critical magnetic field of the iron-based superconductor FeSe

Shubnikov-de Haas (SdH) oscillations and upper critical magnetic field (

Analytical treatment of the de Haas–van Alphen frequency combination due to chemical potential oscillations in an idealized two-band Fermi liquid

H\_{c2}

Hydrostatic pressure anvil cell for electron transport measurements up to 1 GPa under high pulsed magnetic field at liquid helium temperatures

) of the iron-based superconductor FeSe (

Angular and magnetic field dependencies of the magnetoresistance of λ-(BETS)2FeCl4 in the field-restored high conductivity state

T\_c

Upper critical magnetic field of KxFe2−ySe2 and Eu0.5K0.5Fe2As2 single crystals

= 8.6 K) have been studied by tunnel diode oscillator-based measurements in magnetic fields of up to 55 T and temperatures down to 1.6 K. Several Fourier components enter the SdH oscillations spectrum with frequencies definitely smaller than predicted by band structure calculations indicating band renormalization and reconstruction of the Fermi surface at low temperature, in line with previous ARPES data. The Werthamer-Helfand-Hohenberg model accounts for the temperature dependence of

High-frequency magnetic oscillations of the organic metal θ-(ET)4ZnBr4(C6H4Cl2) in pulsed magnetic field of up to 81 T

H\_{c2}