5 research outputs found
High-Field de Haas-van Alphen Effect in non-centrosymmetric CeCoGe3 and LaCoGe3
We report on de Haas-van Alphen effect measurements in the
non-centrosymmetric systems CeCoGe3 and LaCoGe3 in magnetic field up to 28
Tesla. In both compounds, two new high frequencies were observed in high
fields. The frequencies were not detected in previous lower field measurements.
The frequencies do not originate from magnetic breakdown, and, therefore, are
likely to be intrinsic features of the compounds. In CeCoGe3, the corresponding
effective masses are strongly enhanced, being of the order of 30 bare electron
masses.Comment: 3 pages, 4 figures, to be published in Proc. Int. Conf. Heavy
Electrons (ICHE2010) J. Phys. Soc. Jpn. 80 (2011
Pairing competition in a quasi-one-dimensional model of organic superconductors (TMTSF) in magnetic field
We microscopically study the effect of the magnetic field (Zeeman splitting)
on the superconducting state in a model for quasi-one-dimensional organic
superconductors (TMTSF). We investigate the competition between spin
singlet and spin triplet pairings and the
Fulde-Ferrell-Larkin-Ovchinnikov(FFLO) state by random phase approximation.
While we studied the competition by comparison with the eigenvalue of the gap
equation at a fixed temperature in our previous study (Phys. Rev. Lett.
\textbf{102} (2009) 016403), here we obtain both the for each pairing
state and a phase diagram in the (temperature)-(field)-(strength
of the charge fluctuation) space. The phase diagram shows that consecutive
transitions from singlet pairing to the FFLO state and further to
triplet pairing can occur upon increasing the magnetic field when
charge fluctuations coexist with spin fluctuations. In the FFLO state,
the singlet d-wave and triplet -wave components are strongly mixed
especially when the charge fluctuations are strong.Comment: 11 pages, 9 figure
Pairing Symmetry Competition in Organic Superconductors
A review is given on theoretical studies concerning the pairing symmetry in
organic superconductors. In particular, we focus on (TMTSF)X and
-(BEDT-TTF)X, in which the pairing symmetry has been extensively
studied both experimentally and theoretically. Possibilities of various pairing
symmetry candidates and their possible microscopic origin are discussed. Also
some tests for determining the actual pairing symmtery are surveyed.Comment: 16 pages, 8 figures, to be published in J. Phys. Soc. Jpn., special
issue on "Organic Conductors