Two-band electronic mechanism for superconductivity

✍ Scribed by O. Entin-Wohlman; Y. Imry

• Publisher: Elsevier Science
• Year: 1988
• Tongue: English
• Weight: 144 KB
• Volume: 153-155
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(88)90302-4

✦ Synopsis

In our studies of electron-phonon interactions in two bands (1,2,3) as a possible mechanism for high-Tc superconductivity in oxides (4), we noticed a purely electronic two-(or more) band mechanism which leads generally to an attractive component of the electronelectron interaction. This mechanism has been suggested a long time ago by Kondo (5). Here, we point out its probable relevance to high-Tc superconductivity in materials with complex band-structures, derive the form of this effective interaction, apply it to superconductivity in a "semiconductor" model (without necessarily having overlapping bands) and discuss its strength. The attractive interaction in each band arises from a second-order process, in which the two electrons in band 1 scatter by, for example, the Coulomb interaction, to the intermediate state in band 2, and then the two electrons in band 2 are scattered back into band 1, as depicted in Fig. 1.