Thermodynamics and response of a spin-charge-separated superconductor

Thermodynamic and transport properties of a weak-coupling isotropic s-wave superconductor with a spin-charge separated normal state, are described. Tc and the gap parameter Δ(T) are enhanced by spin-charge separation. The ratio 2Δ(0)/kBTc is nonuniversal. Incoherent spectral weight is present below the gap, leading to a superconducting quasiparticle density of states N(ω)∼ω2, |ω|much-lt Δ. For T/Tc much-lt 1, power-law temperature corrections O(T4) to the gap, superfluid density, and Josephson critical current are found. Spin-charge separation leads to a normal fluid density which is nonvanishing at zero temperature, even in the clean limit. The conductance is nonzero at finite frequency in the superconducting state; in particular there is a sharp onset when ω>Δ