Quantum Criticality Near Kondo Breakdown Fixed Point
Thu, Nov. 16th 2006, 11:00
Petit Amphi, LPS Bât. 510, Orsay
I will present a study of the Kondo-Heisenberg model in three dimensions. The mean field phase diagram exhibits a spin liquid phase and a heavy-fermion phase, separated by a quantum critical point where an energy scale associated with Kondo hybridization vanishes. The quantum critical regime of this system has a small, but finite, temperature scale. Above this scale the critical fluctuations associated with the vanishing Kondo hybridization has a dynamical exponent $z=3$, giving rise to a resistivity which has $T log T$ temperature dependence. The transport and thermodynamic properties near this quantum critical point will be discussed in the light of recent experiments on heavy fermion systems.