Extended paraconductivity regime in underdoped cuprates

TL;DR

This paper shows that AL paraconductivity remains robust in underdoped cuprates below T^*, and that deviations from linear resistivity are explained by these fluctuations, highlighting an extended fluctuation regime in the pseudogap phase.

Contribution

It demonstrates the persistence of universal AL paraconductivity in underdoped cuprates and links its disappearance to the loss of Gaussian pair fluctuations at T^*.

Findings

AL paraconductivity is robust below T^* in underdoped cuprates.

Normal state resistivity remains nearly linear in temperature in the pseudogap phase.

Disappearance of paraconductivity correlates with the loss of Gaussian fluctuations at T^*.

Abstract

We reconsider transport experiments in strongly anisotropic superconducting cuprates and we find that universal Aslamazov-Larkin (AL) paraconductivity in two dimensions is surprisingly robust even in the underdoped regime below the pseudogap crossover temperature T^*. We also establish that the underlying normal state resistivity in the pseudogap phase is (almost) linear in temperature, with all the deviations being quantitatively accounted by AL paraconductivity. The disappearence of paraconductivity is governed by the disappearence of gaussian pair fluctuations at an energy scale related to T^*.