Revival of superconductivity in high magnetic fields and a possible pwave pairing in (TMTSF)_{2}PF_{6}
Abstract
From the BCS theory, we derive an equation which accounts for quantum effects of an electron motion along open Fermi surfaces and determines the upper critical field H^{⊥}_{c2}(T) perpendicular to the chains of a quasionedimensional conductor. This equation demonstrates two unusual phenomena: (1) restoration of superconductivity at H>H^{⊥}_{c2}(0) in pwave superconductors, where H^{⊥}_{c2}(0) is the quasiclassical upper critical field; (2) surviving of superconductivity at H^{⊥}_{c2}(0), H_{p}<H<H^{LOFF}_{p} in swave superconductors, where H_{p} is the ClogstonChandrasekhar paramagnetic limiting field; the critical field H^{LOFF}_{p} is introduced in the paper. An analysis of recent experimental data by I. J. Lee, M. J. Naughton, G. M. Danner, and P. M. Chaikin [Phys. Rev. Lett. 78, 3555 (1997)] shows that superconductivity significantly exceeds H^{LOFF}_{p} for b direction of a magnetic field in (TMTSF)_{2}PF_{6}. This demonstrates a strong suppression of the Pauli pair breaking effects and may reflect a pwave pairing of electrons.
 Publication:

Physical Review B
 Pub Date:
 January 1999
 DOI:
 10.1103/PhysRevB.59.R721
 Bibcode:
 1999PhRvB..59..721L
 Keywords:

 74.70.Kn;
 74.60.Ec;
 Organic superconductors