Large magnetic field-induced spectral weight enhancement of high-energy spin excitations in $La_{1.88}Sr_{0.12}CuO_{4}$

TL;DR

This study demonstrates that applying a magnetic field to La_{1.88}Sr_{0.12}CuO_{4} enhances high-energy spin excitations, indicating a field-induced increase in antiferromagnetic correlations within a superconducting state.

Contribution

It reveals a magnetic field-induced spectral weight enhancement of high-energy spin excitations in a cuprate superconductor, suggesting electronically inhomogeneous states are affected by magnetic fields.

Findings

Spectral weight of two-magnon peak increases linearly with magnetic field.

Enhancement factor exceeds two at 14 Tesla.

Effect is absent at higher temperatures and in undoped La_{2}CuO_{4}.

Abstract

We report electronic Raman scattering experiments on a superconducting ${\rm La_{1.88}Sr_{0.12}CuO_{4}}$ single crystal in a magnetic field. At low temperatures, the spectral weight of the high-energy two-magnon peak increases linearly with field and is amplified by a factor of more than two at 14 T. The effect disappears at elevated temperatures and is not present in undoped ${\rm La_{2}CuO_{4}}$. This observation is discussed in terms of an electronically inhomogeneous state in which the field enhances the volume fraction of a phase with local antiferromagnetic order at the expense of the superconducting phase.