Speaker: Peter Wölfle, Karlsruhe Institute of Technology, Germany
Abstract: Following a brief general introduction into quantum phase transitions the case of antiferromagnetic transitions in heavy fermion metals is discussed. It is shown that in certain cases the effective mass of fermionic quasiparticles diverges at the critical point. Using an extension of Landau quasiparticle theory the coupling of the critical behavior in the fermionic and bosonic sector is shown to lead to a new type of scaling behavior with unusual critical exponents. The theory accounts well for the up to now unexplained critical behavior of YbRh2Si2.