title: Superconducting state of the organic conductor (TMTSF)2ClO4.
abstract: (TMTSF)2ClO4 is a quasi-one-dimensional organic conductor and superconductor with Tc=1.4 K, and one of at least two Bechgaard salts observed to have upper critical fields far exceeding the paramagnetic limit. Nevertheless, the 77Se NMR Knight shift at low fields reveals a decrease in spin susceptibility chi(s) consistent with singlet spin pairing. The field dependence of the spin-lattice relaxation rate at 100 mK exhibits a sharp crossover (or phase transition) at a field Hs approximately 15 kOe, to a regime where chi(s) is close to the normal state value, even though Hc2>> Hs.
authors.affiliation: Department of Physics Astronomy, UCLA, Los Angeles, California 90095, USA.
authors.forename: J
authors.initials: J
authors.lastname: Shinagawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kurosaki
authors.forename: F
authors.initials: F
authors.lastname: Zhang
authors.forename: C
authors.initials: C
authors.lastname: Parker
authors.forename: S E
authors.initials: SE
authors.lastname: Brown
authors.forename: D
authors.initials: D
authors.lastname: Jérome
authors.forename: J B
authors.initials: JB
authors.lastname: Christensen
authors.forename: K
authors.initials: K
authors.lastname: Bechgaard