에피 산화물연구실에서 전남대학교 물리학과 고아라 교수님과 Oak Ridge National Laboratory의 옥종목 박사님을 초청하여 아래와 같이 세미나를 개최합니다.

학과 구성원 여러분의 많은 참석을 부탁 드립니다.

온라인으로 진행되는 Webniar(Web+Seminar)이며, Webex meetings 프로그램을 통해 진행됩니다.

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○ Date/time: 2021. 2. 18 (Thu.) 오전 11시 & 오후 2시

○ Speaker: 고아라 교수님 (전남대학교 물리학과)

○ time: 11:00 am

○ Title: Hund's metallicity in the vicinity of a Van Hove singularity

○ Abstract: Hund's metallicity or spin-freezing refers to strong paramagnetic fluctuations and bad metallic behavior driven by Hund's coupling in multi-orbital systems. The effect is prominent at even filling of the three-band system, relevant to ruthenate t2g systems. The low-temperature response of the Hund's metal is an intriguing topic, considering its potential relevance to superconductivity. We perform systematic dynamical mean-field calculations for a three-band model combined with electronic structures accompanying van Hove singularity, including a tight-binding Hamiltonian obtained by the density functional theory for Sr2RuO4. We find that the van Hove singularity significantly enhances Hund's metallicity at relatively low temperatures. We discuss its origin by comparing the results to the Bethe lattice counterpart.

○ Speaker: 옥종목 박사님 (Materials Science and Technology Division, Oak Ridge National Laboratory)

○ time: 14:00 pm

○ Title: Correlated topological phases in strongly correlated heterostructures

○ Abstract: “Strong correlation,” represented by unconventional superconductors, and “Topology,” which has started from the quantum Hall effects and developed into topological insulators, have been recognized as two most important areas in condensed matter physics for the past 50 years. Recently, two areas have begun to merge, creating new concepts such as correlated topological materials. Understanding these materials is a fundamental task to realize the future technologies including quantum computing. The most important question is how correlated electrons are affected by topology and what phenomena can emerge from their interactions. From this point of view, I aspire to find correlated materials which have topological characteristics. In this talk, I will introduce potential correlated topological phases and related phenomena found in strongly correlated heterostructures.