Paraconductivity of pseudogapped superconductors
Abstract
We calculate AslamazovLarkin (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 Cooperpair 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 ≤ɛ_{1}≪1 . Characteristic scale ɛ_{1} is much larger than the width ɛ_{2} of the thermodynamical critical region, that is determined via the Ginzburg criterion, ɛ_{2}≈ɛ_{1}^{d} . We argue that in the intermediate region ɛ_{2}≤ɛ ≤ɛ_{1} , 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 ≤ɛ_{2} ; in particular, conductivity occurs to be strongly inhomogeneous in real space.
 Publication:

Physical Review B
 Pub Date:
 January 2018
 DOI:
 10.1103/PhysRevB.97.014506
 arXiv:
 arXiv:1710.02363
 Bibcode:
 2018PhRvB..97a4506P
 Keywords:

 Condensed Matter  Superconductivity
 EPrint:
 16 pages, 10 figures