Remanence effects in the electrical resistivity of spin glasses

¹ Institut Néel - B.P. 166, 38042 Grenoble Cedex 09, France, EU
² Institut de Physique Nucléaire de Lyon, Université de Lyon, Université de Lyon1, CNRS & IN2P3 04 rue Enrico Fermi, 69622 Villeurbanne Cedex, France, EU
³ Laboratoire de Physique, École Normale Supérieure de Lyon - 47 allée d'Italie, 69007 Lyon, France, EU
⁴ Université Joseph Fourier - B.P. 53, 38041 Grenoble Cedex 09, France, EU
⁵ Institut Universitaire de France - 103 boulevard Saint-Michel, 75005 Paris, France, EU

^a Laurent.Saminadayar@grenoble.cnrs.fr

Received: 16 November 2010
Accepted: 4 January 2011

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 ρ(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 T_sg: upon Field Cooling (fc), we observe clear deviations of ρ(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.