Spin glasses in a magnetic field: Phase diagram and dynamics

✍ Scribed by F. Lefloch; J. Hammann; M. Ocio; E. Vincent

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 764 KB
• Volume: 203
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)90278-x

✦ Synopsis

We have measured the properties of the CdCra.7Ino.3S 4 spin glass in a magnetic field. In a first part, we show that the onset of irreversibilities allows the determination of cross-over lines, which can be nicely fitted to the mean-field predictions of critical lines. We have thus determined a field-temperature phase diagram of this spin glass. In a second part, we study how the aging phenomena are affected by the presence of a field. The temperature cycling experiments, which reveal a hierarchical organization of the metastable states, yield the same result in a field. In contrast, field cycling experiments are not directly sensitive to the hierarchy of the states; a field change brings the system from one set of hierarchically organized states to another. At last, we show that field quenching yields some of the general aging properties which are usually observed after a temperature quench.