Mean-field description of a dilute s–d system

✍ Scribed by J. Maćkowiak

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 277 KB
• Volume: 336
• Category: Article
• ISSN: 0378-4371
• DOI: 10.1016/j.physa.2003.12.039

✦ Synopsis

The Feynman-Kac theorem and Bogolyubov inequality are applied to obtain a lower bound and an upper bound to the free energy of the s-d Hamiltonian with locally smeared interactions between electrons and impurities. The two bounds, which express in terms of the free energy of impurities in a mean ÿeld and electrons in a ÿeld of barriers and wells localized at the impurity sites, are almost equal if the impurity concentration is su ciently small or s-d coupling su ciently weak.