Session G7 - Quantum Criticality in Correlated Electron Systems.
INVITED session, Tuesday morning, March 04
Room 17A, Austin Convention Center
We review the anomalous properties of heavy fermion compounds like CeCu_6-xAu_x or CeMIn_5 close to a zero temperature phase transition called a quantum critical point. Anomalous behavior of the resistivity, specific heat and magnetic properties observed in various compounds suggests a fundamental breakdown of the Fermi liquid theory. Recent measurements on YbRh_2Si_2, field-tuned through the quantum critical point, provide interesting insights on the evolution of the Fermi liquid close to criticality. We discuss the possibility of a kind of spin-charge separation at the quantum critical point and make some remarks about its possible link with the underscreened Kondo model.