Bodensiek Oliver, Žitko Rok, Vojta Matthias, Jarrell Mark, Pruschke Thomas
Institut für Theoretische Physik, Universität Göttingen, 37077 Göttingen, Germany.
Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia.
Phys Rev Lett. 2013 Apr 5;110(14):146406. doi: 10.1103/PhysRevLett.110.146406.
The explanation of heavy-fermion superconductivity is a long-standing challenge to theory. It is commonly thought to be connected to nonlocal fluctuations of either spin or charge degrees of freedom and therefore of unconventional type. Here we present results for the Kondo-lattice model, a paradigmatic model to describe heavy-fermion compounds, obtained from dynamical mean-field theory which captures local correlation effects only. Unexpectedly, we find robust s-wave superconductivity in the heavy-fermion state. We argue that this novel type of pairing is tightly connected to the formation of heavy quasiparticle bands and the presence of strong local spin fluctuations.
