Spin-triplet `f-wave' pairing proposed for an organic superconductor (TMTSF)_2 PF_6

Abstract

By examining how the spin- and/or charge-fluctuation exchange can contribute to pairing instabilities, we propose that a spin-triplet f-wave-like pairing with a d-vector perpendicular to the b-axis may be realized in (TMTSF)_2 PF_6 due to (i) a quasi-one-dimensional Fermi surface, (ii) a coexistence of 2k_F charge fluctuations and spin fluctuations, and (iii) an anisotropy in spin fluctuations. Fluctuation-exchange study for the Hubbard model confirms the point (i), while a phenomelogical analysis is given for (ii) and (iii). The proposed pairing is consistent with various experiments.

5 pages, 4 figures, RevTeX, uses epsf.sty and multicol.sty