Author/Authors :
Balthes، نويسنده , , E. and Proust، نويسنده , , C. and Audouard، نويسنده , , A. and Brossard، نويسنده , , L. and Schweitzer، نويسنده , , D. and Heinen، نويسنده , , I. E. Keller and P. V. Trusov ، نويسنده , , H.J. and Strunz، نويسنده , , W. and Jansen، نويسنده , , A.G.M. and Steep، نويسنده , , E.، نويسنده ,
Abstract :
The electronic system of the organic superconductor κ-(BEDT-TTF)2I3 (BEDT-TTF = bis(ethylenedithiolo)tetrathiafulvalene) is identified as extremely two-dimensional (2D). The topology of the Fermi surface (FS) was investigated by means of Shubnikov-de Haas (SdH) as well as de Haas-van Alphen (dHvA) experiments focusing on the verification of the 2D character of the system. This two-dimensionality specially takes effect as soon as the magnetic field is oriented exactly perpendicular to the conducting planes (i.e. Θ = 0°). Under such conditions strong anomalous damping effects in the field and temperature dependence of quantum oscillation amplitudes are observed. These anomalous damping effects are discussed in terms of the occurrence of quasi-particle excitations with fractional statistics (QPFS) which may only occur in extremely 2D systems at high magnetic fields and low temperatures (i.e., only when ħωC ≫ kBT). Taking up these requirements, the aim of this work is to quantify the extreme two-dimensionality of the electronic system of κ-(BEDT-TTF)2I3 and to show that the observed damping effects in fact are determined by the ratio ħωC/kBT. These facts may support the interpretation of the observed damping effects of quantum oscillation amplitudes at high magnetic fields, low temperatures and Θ = 0° as generated by the possible occurrence of such QPFS.
