title: Spin-triplet pairing instability of the spinon fermi surface in a U(1) spin liquid.
abstract: Recent experiments on the organic compound kappa-(ET)2Cu2(CN)3 have provided a promising example of a two-dimensional spin liquid state. This phase is described by a two-dimensional spinon Fermi sea coupled to a U(1) gauge field. We study Kohn-Luttinger-like pairing instabilities of the spinon Fermi surface due to singular interaction processes with twice-the-Fermi-momentum transfer. We find that under certain circumstances the pairing instability occurs in odd-orbital-angular momentum or spin-triplet channels. Implications to experiments are discussed.
authors.affiliation: Department of Physics and Joint Quantum Institute, University of Maryland, College Park, Maryland 20742-4111, USA.
authors.forename: Victor
authors.initials: V
authors.lastname: Galitski
authors.forename: Yong Baek
authors.initials: YB
authors.lastname: Kim