Isotope Effect in the Superfluid Density of HTS Cuprates: Stripes, Pseudogap and Impurities

TL;DR

This paper investigates how isotope effects in cuprates reveal the roles of stripes, pseudogap, and impurities in high-temperature superconductivity, showing they are distinct yet coexist and influence superconducting properties.

Contribution

The study demonstrates that isotope effects in superfluid density and $T_c$ can differentiate the roles of stripes and pseudogap in cuprates, highlighting their coexistence and competition with superconductivity.

Findings

Isotope effects distinguish between stripes and pseudogap roles.

Stripes and pseudogap are separate phenomena that both compete with superconductivity.

Impurity scattering influences isotope effects and superconducting properties.

Abstract

Underdoped cuprates exhibit a normal-state pseudogap, and their spins and doped carriers tend to spatially separate into 1- or 2-D stripes. Some view these as central to superconductivity, others as peripheral and merely competing. Using La$_{2-x}$Sr$_x$Cu$_{1-y}$Zn$_y$O$_4$ we show that an oxygen isotope effect in $T_c$ and in the superfluid density can be used to distinguish between the roles of stripes and pseudogap and also to detect the presence of impurity scattering. We conclude that stripes and pseudogap are distinct, and both compete and coexist with superconductivity.