Muon Spin Rotation Measurements of Heterogeneous Field Response in Overdoped La2-xSrxCuO4

TL;DR

This study uses muon spin rotation to reveal significant magnetic heterogeneity in overdoped La2-xSrxCuO4, challenging the Fermi-liquid model and suggesting localized magnetic regions around dopants.

Contribution

It provides new experimental evidence of magnetic heterogeneity in overdoped cuprates, indicating complex local magnetic responses not explained by traditional models.

Findings

Large magnetic field broadening persists at high temperatures.

Field response follows Curie-Weiss temperature dependence.

Heterogeneity increases with doping level.

Abstract

Transverse-field muon spin rotation measurements of overdoped La2-xSrxCuO4 reveal a large broadening of the local magnetic field distribution in response to applied field, persisting to high temperatures. The field-response is approximately Curie-Weiss like in temperature and is largest for the highest doping investigated. Such behaviour is contrary to the canonical Fermi-liquid picture commonly associated with the overdoped cuprates and implies extensive heterogeneity in this region of the phase diagram. A possible explanation for the result lies in regions of staggered magnetization about dopant cations, analogous to what is argued to exist in underdoped systems.