Quantum Criticality in Heavy Fermion Metals

Understand

Quantum criticality describes the collective fluctuations of matter undergoing a second-order phase transition at zero temperature.

• Heavy fermion metals have in recent years emerged as prototypical systems to study quantum critical points.
• There have been considerable efforts, both experimental and theoretical, which use these magnetic systems to address problems that are central to the broad understanding of strongly correlated quantum matter.
• Here, we summarize some of the basic issues, including i) the extent to which the quantum criticality in heavy fermion metals goes beyond the standard theory of order-parameter fluctuations, ii) the nature of the Kondo effect in the quantum critical regime, iii) the non-Fermi liquid phenomena that accompany quantum criticality, and iv) the interplay between quantum criticality and unconventional superconductivity.