Pressure induced quantum phase transitions in d- and f-electron systems

V. A. Sidorov

Institute for High Pressure Physics of Russian Academy of Sciences,

142190, Troitsk, Moscow


    Pressure is a convenient tuning parameter which can move the system through the quantum phase transition. This transition may be continuous, accompanied by the quantum critical phenomena such as Non-Fermi Liquid behavior, or discontinuous 1-st order-like. I will discuss the experimental results concerning transport and thermodynamic properties of CePt2In7, CeCoSi and CoS2 which exhibit quantum phase transitions at high pressure. In CePt2In7 the heavy fermion superconductivity was found near the quantum critical point and its P-T diagram is very similar to that of CeRhIn5. At high pressure CeCoSi has a diversity of ground states, Ce- and Co-sublattice magnetism, AFM quantum phase transition and Ce-related valence transition. Itinerant ferromagnet CoS2 has a first order-like transition without quantum critical phenomena, accompanied by destabilization of the magnetic moment. Hydrostatic pressure technique combined with a precise ac-calorimetry allows us to perform analysis of the entropy changes across the quantum phase transition.

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