Pressure and magnetic field induced quantum criticality in Yb-based heavy fermion compounds

位于量子临界点（QCP）附近的重费米子金属的基态性质是近年来人们最感兴趣的课题之一。为了获得在压力和磁场作用下Yb基重费米子系统量子临界行为的新认识，我们研制了一种新型的高压池。结合压力和磁场调谐的比热测量揭示了YbCo_2Zn_3的一种新相图<20>。在YbNi_3Ga_9中还发现了压致铁磁有序。

In recent years, one of the most interesting topics is the ground state properties of heavy fermion metals located at or close to a quantum critical point(QCP). To obtain the new insights on the quantum critical behavior in Yb-based heavy fermion systems under pressure and magnetic field, we have developed new type of high pressure cell. Combined pressure-and magnetic-field-tuned specific heat measurements reveal a novel phase diagram in YbCo_2Zn_<20>. We also found the pressure-induced ferromagnetic order in YbNi_3Ga_9.