Tunneling spectroscopy on correlated electron systems

✍ Scribed by J. Aarts; A.P. Volodin

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 429 KB
• Volume: 206-207
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)00363-z

✦ Synopsis

Different current methods for tunneling spectroscopy are discussed. Spectroscopic measurements at low temperatures involving either vacuum tunneling or 'small-junction' tunneling are presented on different systems which show gaps in their density of states. In the Kondo insulators FeSi and CeNiSn, we found gaps 2A of about 100 meV and 10 meV, respectively. In the heavy fermion materials UPd2AI 3 and URu2Si2, we found gaps of about 10 meV below the antiferromagnetic ordering when tunneling along the ab planes. No gap was found along the c-axis, so that the normal state of these superconductors appears strongly anisotropic.