Nuclear Magnetic Resonance Studies of Heavy Fermion Materials

Nicholas J Curro

University of California, Davis, USA


    The NMR Knight shift and spin lattice relaxation rate probe the local spin susceptibility of the electrons that couple to the nuclei via the hyperfine interaction. In strongly correlated materials these quantities often provide important clues about the electronic behavior and new phases that may emerge at low temperature. In Kondo lattice systems the Knight shift and magnetic spin susceptibility probe different correlations between the conduction spins and the local f-spins. These correlations reflect changes to the electronic system, such as the onset of coherence and hybridization, and several examples of these Knight shift anomalies will be presented. In the second part of the talk, NMR measurements of Kondo lattice systems with local impurities will be discussed. Impurities that are introduced in a controlled fashion can reveal critical new information about the underlying order parameters and correlated behavior.

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