Study of the relation between magnetism, superconductivity and quantum criticality on 4f-electron compounds under
extreme conditions
일 시 : 2020년 10월 15일 목요일 16:00
연 사 : 서 순 범 박사 (성균관대 물리학과)
장 소 : 자연과학관 747호
초 록
In condensed matter physics, novel quantum states of matter may emerge near zero temperature, including unconventional superconductivity, complex magnetic order, and non-Fermi liquid behavior. In order to create predictive understanding of these new phases unexpected by conventional theories, proper materials and control parameters are necessary. Here we demonstrate methods of investigating new quantum states of matter in f-electron systems using a variety of experimental techniques under extreme conditions of low temperature, hydrostatic pressure, and high magnetic field. We discuss results that reveal quantum states near the quantum critical point (QCP) of an f-electron compound at which a quantum phase transition is driven by quantum fluctuations. In particular, doping effects on the pressure induced antiferromagnetic QCP in CeRhIn5 have been studied to probe the relationship between QCP and superconducting phase. In addition, we discuss results that exhibit novel quantum states in various Ce based compounds under pressure, including nematic phase coupled with magnetism and pseudogap phase near a superconducting phase, akin to high-Tc superconductors. In particular, recently discovered nematic state in CeAuSb2 will be discussed through the experimental results as well as theoretical model.