Venue: Search of Quantum Criticality in Novel Strongly Correlated Systems

Speaker: Zhuo Feng, Quantum Matter Group, Cavendish Laboratory, J J Thomson Avenue, Cambridge, UK

Time:  28 December 2011,16:00-17:00

Location: Room 423,  Academic Building 12,  Yuquan Campus

Abstract:

Quantum critical phenomena (QCP) have over the past decade been investigated primarily in ferromagnetic or nearly ferromagnetic d-electron systems and in antiferromagnetic f-electron systems. We are presenting some new strongly correlated systems prepared by our group to explore novel QCPs. The d-electron system YFe2Ge2 exhibits Non-Feimi-Liquid temperature dependences in electrical resistivity and specific heat capacity, indicating a close-by quantum critical point associated with antiferromagnetism or spin density waves. The full loss of electrical resistivity below 2K also suggests a promising superconductivity in this material. The f-electron Cerium-based f-electron system CeSb2, which shows ferromagnetism unusually, undergoes a structural transition near room temperature and complicated magnetic structure below 15K at ambient pressure. The structural transition is gradually suppressed by pressure and disappeared together with magnetic ordering above 16kbar. At high pressure regime, the CeSb2 displays typical heavy fermion-like temperature dependence of the resistivity with a very low coherence temperature.