"Superconductivity from repulsive interactions"

Speaker: 
Andrey Chubukov
Institution: 
Univ. of Minnesota
Speaker Link: 
Date: 
Thursday, November 13, 2014
Time: 
3:30 pm
Location: 
RH 101
 

 
ABSTRACT:
 
In BCS theory of superconductivity, electron-phonon interaction is a glue that overcomes Coulomb repulsion and binds fermions into pairs which then condense and super-conduct.  In my talk, I review recent and not so recent works aiming to understand whether a nominally repulsive Coulomb interaction can by itself give rise to a superconductivity.  I first discuss a generic scenario of the pairing by electron-electron interaction, put forward by Kohn and Luttinger back in 1965, and then discuss modern studies of the electronic mechanisms of superconductivity in the lattice systems which model cuprates, Fe-pnictides, and doped graphene.  I  show that the pairing in all three classes of materials can be viewed as lattice version of Kohn-Luttinger physics, despite that the pairing symmetries are different.  I discuss under what conditions the pairing occurs and rationalize the need to do parquet renormalization-group studies.  I also analyze the interplay between superconductivity and density-wave instabilities.

*Co-sponsored by ICAM

Host: 
Sasha Chernyshev