아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다. 4시부터 2층 라운지세미나실에 다과를 준비하오니 많은 참석 부탁드립니다 아 래 제목: Probing hidden magnetism and quantum criticality in unconventional superconductors 연사: 박 두 선 교수 (성균관대학교 물리학과) 일시: 2009년 3월 13일(금) 오후4:30 장소: 물리학과 세미나실(31355호실) 초록: Phase transitions are everywhere in our daily life, such as the liquid-gas transition seen as water vaporizes from a hot pot. Those classical phase transitions with which we are familiar are governed by random thermal motion of the constituent atoms and show a universal behavior independent of system-specific properties. Recently, a new type of phase transition has been proposed to occur at absolute zero temperature. In contrast to classical, thermally-driven transitions, a quantum-phase transition at zero temperature is driven by fluctuations or zero-point motion associated with Heisenberg’ s uncertainty principle. Experiments have shown that new quantum fluids, qualitatively different from conventional Landau-Fermi liquids, appear in the vicinity of quantum-phase transitions and could become a source of exotic quantum states. One candidate for the emerging states is unconventional superconductivity, which is often observed as an antiferromagnetic phase boundary approaches zero temperature. A well known example is superconductivity in the high-Tc cuprates. Invariably though, a dome of superconductivity intervenes to hide magnetism and prevents proof that a magnetic quantum- critical point exists. Applying extreme conditions to the heavy-fermion superconductor CeRhIn5, we explicitly identify the so-far presumed quantum-critical point inside the superconducting dome. This discovery suggests a common relationship among hidden magnetism, quantum criticality, and unconventional superconductivity in classes of strongly correlated electron materials. Reference [1] T. Park et al., “Isotropic quantum scattering and unconventional superconductivity,” Nature 456, 366-368 (2008). [2] T. Park et al., “Hidden magnetism and quantum criticality in the heavy fermion superconductor CeRhIn5,” Nature 440, 65 (2006). [3] T. Park et al., “Electronic duality in strongly correlated matter,” Proc. Nat. Acad. Sci.105, 6825-6828 (2008). [4] T. Park et al., “Probing the nodal gap in the pressure-induced heavy fermion superconductor CeRhIn5,” Phys. Rev. Lett. 101, 177002 (2008). [5] T. Park et al., “Direct observation of nodal quasiparticles in an unconventional superconductor: field-angle dependent heat capacity of YNi2B2C,” Phys. Rev. Lett. 90, 177001 (2003). http://physics.skku.ac.kr/ppt/0313.ppt