Remanence effects in the electrical resistivity of spin glasses

TL;DR

This study measures the electrical resistivity of mesoscopic spin glasses at low temperatures, revealing remanence effects at weak magnetic fields that align with theoretical predictions and magnetic susceptibility signatures of spin glass transitions.

Contribution

It provides experimental evidence of remanence effects in electrical resistivity of spin glasses at very weak magnetic fields, supporting theoretical models.

Findings

Resistivity shows a maximum at a temperature consistent with theory.

Remanence effects appear even at magnetic fields in the Gauss range.

Deviations between FC and ZFC resistivity are observed below Tsg.

Abstract

We have measured the low temperature electrical resistivity of Ag : Mn mesoscopic spin glasses prepared by ion implantation with a concentration of 700 ppm. As expected, we observe a clear maximum in the resistivity (T ) at a temperature in good agreement with theoretical predictions. Moreover, we observe remanence effects at very weak magnetic fields for the resistivity below the freezing temperature Tsg: upon Field Cooling (fc), we observe clear deviations of (T ) as compared with the Zero Field Cooling (zfc); such deviations appear even for very small magnetic fields, typically in the Gauss range. This onset of remanence for very weak magnetic fields is reminiscent of the typical signature on magnetic susceptibility measurements of the spin glass transition for this generic glassy system.