Itinerant ferromagnetism and superconductivity were traditionally believed to represent incompatible forms of electronic order that are well described by the Fermi liquid model of the metallic state or extensions thereof. The itinerant ferromagnet ZrZn_2 exhibits in contrast superconductivity in the milli-Kelvin temperature range that vanishes above the critical pressure p_c where ferromagnetism is suppressed. This suggests that itinerant ferromagnetism may be a precondition for certain forms of superconductivity. The itinerant electron magnet MnSi exhibits, on the other hand, a sharp change from a Fermi liquid T~2 resistivity to a T~(3/2) temperature dependence over an exceptionally large temperature range in the normal metallic state above the critical pressure p_c for which magnetic order is suppressed. The latter property is not consistent with the predictions of the Fermi liquid theory of the normal metallic state. When taken together the superconductivity and non-Fermi liquid normal state may highlight inconsistencies of the current theory of quantum criticality.
展开▼
机译：传统上据信流入的铁磁性和超导性代表了金属状态的费米液体模型或其延伸的良好形式的电子顺序形式。在毫在抑制铁磁性的临界压力P_C上方的毫骨温度范围内，潮流量铁磁性Zrzn_2在毫在临界压力P_C上方的逆向超导中表现出。这表明流入的铁磁性可能是某些形式的超导性的前提。另一方面，Itinerant Electron Magn MNSI表现出从Fermi液体T〜2电阻率的急剧改变到T〜（3/2）温度依赖性在临界压力上方的正常金属状态下的普通金属状态下的特殊温度范围内抑制了磁性秩序。后者属性与正常金属状态的费米液理论的预测不一致。当一起使用超导性和非费米液态状态可能突出显示当前量子临界性理论的不一致。
展开▼
