Paraconductivity of pseudogapped superconductors

We calculate Aslamazov-Larkin (AL) paraconductity σ_AL(T ) for a model of strongly disordered superconductors (dimensions d =2 ,3 ) with a large pseudogap whose magnitude strongly exceeds transition temperature T_c. We show that, within Gaussian approximation over Cooper-pair fluctuations, paraconductivity is just twice larger that the classical AL result at the same ɛ =(T -T_c) /T_c . Upon decreasing ɛ , Gaussian approximation is violated due to local fluctuations of pairing fields that become relevant at ɛ ≤ɛ₁≪1 . Characteristic scale ɛ₁ is much larger than the width ɛ₂ of the thermodynamical critical region, that is determined via the Ginzburg criterion, ɛ₂≈ɛ₁^d . We argue that in the intermediate region ɛ₂≤ɛ ≤ɛ₁ , paraconductivity follows the same AL power law, albeit with another (yet unknown) numerical prefactor. At further decrease of the temperature, all kinds of fluctuational corrections become strong at ɛ ≤ɛ₂ ; in particular, conductivity occurs to be strongly inhomogeneous in real space.