Doping effect on the anomalous behavior of the Hall effect in electron-doped superconductor Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$

TL;DR

This study investigates how doping influences the Hall effect in Nd$_{2-x}$Ce$_x$CuO$_{4+ delta}$, revealing the coexistence of electron-like and hole-like carriers and explaining the sign reversal in the mixed state.

Contribution

It provides new insights into the doping-dependent transport properties and the coexistence of charge carriers in electron-doped cuprate superconductors.

Findings

Existence of both electron-like and hole-like contributions to transport.

Anomalous Hall sign reversal linked to flux-flow regime of two carrier types.

Doping influences the balance of charge carriers in the material.

Abstract

Transport properties of Nd$_{2-x}$Ce$_x$CuO$_{4+\delta}$ single crystal films are investigated in magnetic fields $B$ up to 9T at $T$=(0.4-4.2)K. An analysis of normal state (at $B>B_{c2}$) Hall coefficient $R_H$$^n$ dependence on Ce doping takes us to a conclusion about the existence both of electron-like and hole-like contributions to transport in nominally electron-doped system. In accordance with $R_H$$^n$(x) analysis an anomalous sign reversal of Hall effect in mixed state at $B<B_{c2}$ may be ascribed to a flux-flow regime for two types of carriers with opposite charges.