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4시 20분부터 제1과학관 31214 e+강의실에서 다과를 준비하오니 많은 참석 부탁드립니다.

아 래

Title: Electronic structures of strongly-correlated systems

Speaker: Prof.  Joo Yull Rhee (Department of Physics, SKKU)

Date & Time: Sep. 9 (Wed.) 2015, 4:30 PM 

Place: Natural Science 1,  Room No. 31214

Abstract: If the electrons are spatially localized they acts differently from when they were itinerant. The strong on-site Coulomb interactions among localized electrons lead to the appearance of variety of peculiar properties. In some Ce-based compounds it is commonly believed  that the Kondo interaction might cause some peculiar properties, such as heavy-fermion behavior, quantum criticality (QC), non Fermi-liquid behavior, and so on. In the quantum-critical region, it is not possible to describe the phase transition by using the Landau's theory of order parameter. Recently the orbital anisotropy in heavy-fermion systems is crucial ingredient for QC. In our electronic-structure calculations indeed indicate that the anisotropy of f-orbital in some Ce-based compounds is very important for the appearance of QC. Another interesting area of strongly-correlated systems is a class of multiferroic materials. A typical example of multiferroics is BiFeO3, which exhibit both antiferromagnetic and ferroelectric behaviors. Although the compound is intensively studied owing to its multiferroic behavior, its crystal structure is still unclear. There are several suggestions for the crystal structures. In our calculations indicate that the triclinic structure is the most appropriate structure. In addition, only the triclinic structure results in a semiconducting behavior.