Exchange enhancement of the electron-phonon pair interaction

✍ Scribed by D. Manske; C.T. Rieck; D. Fay

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 144 KB
• Volume: 235-240
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)92285-3

✦ Synopsis

The critical temperature of lugh-Tc superconductors is determined, at least m part, by the electron-phonon coupling. We include the effect of an exchange mteracuon between the electrons and calculate the renormalization of the bare phonon frequenoes and the electron-phonon verticies in a random phase approximation and obt,'un a strongly enhanced attractive phonon-induced electron-electron mteractton. Using Fast Fourier Transform teclmiques, the weak-couphng selfcons~stency equation for the order parameter is solved in the 2D first Briilouin zone for die Emery taght-bindmg band with different band fillings. The enhancement of Tc arises prtmanly from the softening of the phonon frequencies rather than the vertex renormahzation.