High field magnetoresistivity of epitaxial La2-xSrxCuO4 thin films

TL;DR

This study reports large positive magnetoresistivity in La2-xSrxCuO4 thin films at temperatures well above Tc, suggesting the presence of superconducting pairs and fluctuations in the pseudogap regime.

Contribution

It provides evidence of significant magnetoresistance above Tc linked to superconducting fluctuations and pairs, supporting a close relation between pseudogap and superconductivity.

Findings

Large positive magnetoresistivity observed above Tc

Magnetoresistance linked to superconducting fluctuations and pairs

Supports pseudogap-superconductivity connection

Abstract

A large positive magnetoresistivity (up to tens of percents) is observed in both underdoped and overdoped superconducting La2-xSrxCuO4 epitaxial thin films at temperatures far above the superconducting critical temperature Tc. For the underdoped samples, this magnetoresistance far above Tc cannot be described by the Kohler rule and we believe it is to be attributed to the influence of superconducting fluctuations. In the underdoped regime, the large magnetoresistance is only present when at low temperatures superconductivity occurs. The strong magnetoresistivity, which persists even at temperatures far above Tc, can be related to the pairs forming eventually the superconducting state below Tc. Our observations support the idea of a close relation between the pseudogap and the superconducting gap and provide new indications for the presence of pairs above Tc.