Thursday morning seminar coming up

[Cond.Matt. & Stat.Mech.Section]

  SEMINAR on   Disorder and strong electron correlations



Thursday, 6 May      -  11:30 a.m.



Luigi Stasi Seminar Room,  Leonardo Building - first floor





Matthias VOJTA      ( University of Cologne )



"Quantum-critical Kondo screening   in graphene"



Abstract



Electrons in graphene provide an essentially perfect realization of 2d  
Dirac fermions. Introducing magnetic impurities then allows to study  
the so-called pseudogap Kondo effect, where a vanishing host density  
of states causes a quantum phase transition between phases with  
screened and unscreened impurity moment.  In the talk, I will discuss  
the rich Kondo physics in graphene, including orbital degrees of  
freedom and quantum criticality. In particular, I will analyze the  
pseudogap Kondo model in the presence of a finite chemical potential.   
A striking prediction of the theory is an extreme asymmetry of  
impurity properties between electron and hole doping over a wide  
parameter range which can be traced back to the nature of the quantum  
critical point.