Photosensitivity of La2CuO4 in the vicinity of the phase boundary antiferromagnet-spin glass

TL;DR

This study investigates how weak optical illumination affects the optical and magnetic properties of La2CuO4 near its antiferromagnet-spin glass phase boundary, revealing high sensitivity to charge carrier density.

Contribution

It provides new insights into the optical and magnetic responses of La2CuO4 near the phase boundary, highlighting the effects of weak illumination on dichroism and magnetic behavior.

Findings

Changes in dichroism under illumination were observed.

Optical and magnetic properties are highly sensitive to charge carrier density.

Reproducibility issues are linked to proximity to the phase boundary.

Abstract

The spectral, temperature and magnetic field dependencies of the linear dichroism in the reflection of light from the surface of an undoped single crystal of La2CuO4 are studied. The changes of the dichroism absolute value and its response to the external magnetic field induced by a weak optical illumination were detected. The set of experimental results is analyzed from the point of view of the high sensitivity of optical and magnetic properties of cuprates to the density of charge carriers localized in CuO2 planes. It is assumed that the poor reproducibility of some of the observed effects is related to the proximity (on the x-T diagram of magnetic states) to the antiferromagnet - spin glass phase boundary.