Fermi Surface of the Electron-doped Cuprate Superconductor Nd_{2-x}Ce_xCuO_{4} Probed by High-Field Magnetotransport

TL;DR

This study investigates the Fermi surface of Nd$_{2-x}$Ce$_x$CuO$_{4}$ using high-field magnetotransport, revealing a reconstructed Fermi surface in overdoped samples and linking it to superconductivity.

Contribution

It provides direct evidence of Fermi surface reconstruction and magnetic breakdown in electron-doped cuprates, connecting Fermi surface topology with superconducting properties.

Findings

Reconstructed Fermi surface persists up to x≈0.17

Magnetic breakdown causes fast SdH oscillations in overdoped samples

Superlattice potential decreases with doping, vanishing near superconducting doping level

Abstract

We report on the study of the Fermi surface of the electron-doped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_{4}$ by measuring the interlayer magnetoresistance as a function of the strength and orientation of the applied magnetic field. We performed experiments in both steady and pulsed magnetic fields on high-quality single crystals with Ce concentrations of $x=0.13$ to 0.17. In the overdoped regime of $x > 0.15$ we found both semiclassical angle-dependent magnetoresistance oscillations (AMRO) and Shubnikov-de Haas (SdH) oscillations. The combined AMRO and SdH data clearly show that the appearance of fast SdH oscillations in strongly overdoped samples is caused by magnetic breakdown. This observation provides clear evidence for a reconstructed multiply-connected Fermi surface up to the very end of the overdoped regime at $x\simeq 0.17$. The strength of the superlattice potential responsible for the reconstructed Fermi surface is found to decrease with increasing doping level and likely vanishes at the same carrier concentration as superconductivity, suggesting a close relation between translational symmetry breaking and superconducting pairing. A detailed analysis of the high-resolution SdH data allowed us to determine the effective cyclotron mass and Dingle temperature, as well as to estimate the magnetic breakdown field in the overdoped regime.