Electronic inhomogeneity and competing phases in electron-doped superconducting Pr0.88LaCe0.12CuO4

TL;DR

This study reveals that electron-doped Pr0.88LaCe0.12CuO4 exhibits electronic phase separation with coexisting superconducting and magnetic phases, indicating proximity to a quantum critical point affecting its ground state properties.

Contribution

The paper provides direct neutron scattering evidence of phase separation and competing orders in electron-doped cuprates, highlighting their complex ground state near quantum criticality.

Findings

Coexistence of superconducting and antiferromagnetic phases

Neel temperature decreases linearly with Tc

Proximity to a quantum critical point

Abstract

We use neutron scattering to demonstrate that electron-doped superconducting Pr0.88LaCe0.12CuO4 in the underdoped regime is electronically phase separated in the ground state, showing the coexistence of a superconducting phase with a three-dimensional antiferromagnetically ordered phase and a quasi-two-dimensional spin density wave modulation. The Neel temperature of both antiferromagnetic phases decreases linearly with increasing superconducting transition temperature (Tc) and vanishes when optimal superconductivity is achieved. These results indicate that the electron-doped copper oxides are close to a quantum critical point, where the delicate energetic balance between different competing states leads to microscopic heterogeneity.