Hole-pocket-driven superconductivity and its universal features in the electron-doped cuprates

TL;DR

This study reveals that hole pockets play a crucial role in driving superconductivity in electron-doped cuprates, unifying understanding across doping types through magnetoresistivity and superfluid density measurements.

Contribution

It provides the first comprehensive evidence linking hole-pocket-driven superconductivity to universal features in electron-doped cuprates, bridging the gap between hole- and electron-doped phase diagrams.

Findings

Normal state exhibits two-band features including quantum oscillations.

Superconductivity is driven by hole pockets, not electrons.

Uemura scaling applies to the hole component in electron-doped cuprates.

Abstract

After three decades of enormous scientific inquiry, the emergence of superconductivity in the cuprates remains an unsolved puzzle. One major challenge has been to arrive at a satisfactory understanding of the unusual metallic normal state from which the superconducting state emerges upon cooling. A second challenge has been to achieve a unified understanding of hole- and electron-doped compounds. Here we report detailed magnetoresistivity measurements for the archetypal electron-doped cuprate Nd$_{2-x}$Ce$_x$CuO$_{4+{\delta}}$ that, in combination with prior data, provide crucial links between the normal and superconducting states and between the electron- and hole-doped parts of the phase diagram. The characteristics of the normal state (magnetoresistivity, quantum oscillations, and Hall coefficient) and those of the superconducting state (superfluid density and upper critical field) consistently indicate two-band (electron and hole) features and clearly point to hole-pocket-driven superconductivity in these nominally electron-doped materials. We show that the approximate Uemura scaling between the superconducting transition temperature and the superfluid density found for hole-doped cuprates also holds for the small hole component of the superfluid density in the electron-doped cuprates.