PHYSICS/BK21 SEMINAR (08/08/28)
관련링크
본문
"제목: Novel properties in 2D-layered compounds
연사: Dr. Jun Sung Kim[막스플랑크연구소]
일시: 2008 년 8 월 28 일 14:00-15:00
장소: 물리학과세미나실(3-201)
ABSTRACT:
Layered compounds, consisting of two different kinds of layers, provide a playground for tailoring novel properties. By modifying continents of each layers or the coupling between them, the physical properties can be significantly changed, which allows us to unveil the mechanism of the novel properties and/or induce new functionalities. In this talk, I will present three examples: graphite intercalation compounds (GICs), oxide superlattices, and new high-Tc Iron-picnitides. First, unusually high-Tc superconductivity in CaC6 graphite will be discussed in terms of significant electron-phonon coupling due to intercalated metal atoms. By replacing Ca with Sr or applying external pressure, we found that Tc and the superconducting gap anisotropy essentially depends on the graphite layer distance due to sensitive change of electron-phonon coupling. Secondly, atomically abrupt interfaces in superlattices of a Mott- and a band-insulator, LaTiO3 and SrTiO3, will be discussed. The nature of quasi-2-dimensional metallic state at the interface has been investigated using magneto-transport experiments. At low temperatures, we found a rapid change in the Hall resistivity, similar to the anomalous Hall effect, which is often observed in magnetic metals, but in neitherdoped bulk LaTiO3 nor SrTiO3. These results provide the first experimental evidence for the magnetic correlation in the interfacial metallic states, suggesting that the interface between LaTiO3 and SrTiO3 constitutes a new electronic state. Finally, I will show recent investigations on new high-Tc superconductors, Iron-pnictides, consisting of conducting FeAs layers and Rear earths oxide or Alkaline earth layers as a charge reservoir. The highly magnetic metallic state in undoped FeAs layers becomes superconducting by modifying the charge reservoir or applying external pressure. The nature of stripe-like magnetic ordering in the FeAs layer and the effect of various doping on superconductivity will be discussed.
문의처: 이기봉(054-279-2068, kibong@postech.ac.kr)
"
연사: Dr. Jun Sung Kim[막스플랑크연구소]
일시: 2008 년 8 월 28 일 14:00-15:00
장소: 물리학과세미나실(3-201)
ABSTRACT:
Layered compounds, consisting of two different kinds of layers, provide a playground for tailoring novel properties. By modifying continents of each layers or the coupling between them, the physical properties can be significantly changed, which allows us to unveil the mechanism of the novel properties and/or induce new functionalities. In this talk, I will present three examples: graphite intercalation compounds (GICs), oxide superlattices, and new high-Tc Iron-picnitides. First, unusually high-Tc superconductivity in CaC6 graphite will be discussed in terms of significant electron-phonon coupling due to intercalated metal atoms. By replacing Ca with Sr or applying external pressure, we found that Tc and the superconducting gap anisotropy essentially depends on the graphite layer distance due to sensitive change of electron-phonon coupling. Secondly, atomically abrupt interfaces in superlattices of a Mott- and a band-insulator, LaTiO3 and SrTiO3, will be discussed. The nature of quasi-2-dimensional metallic state at the interface has been investigated using magneto-transport experiments. At low temperatures, we found a rapid change in the Hall resistivity, similar to the anomalous Hall effect, which is often observed in magnetic metals, but in neitherdoped bulk LaTiO3 nor SrTiO3. These results provide the first experimental evidence for the magnetic correlation in the interfacial metallic states, suggesting that the interface between LaTiO3 and SrTiO3 constitutes a new electronic state. Finally, I will show recent investigations on new high-Tc superconductors, Iron-pnictides, consisting of conducting FeAs layers and Rear earths oxide or Alkaline earth layers as a charge reservoir. The highly magnetic metallic state in undoped FeAs layers becomes superconducting by modifying the charge reservoir or applying external pressure. The nature of stripe-like magnetic ordering in the FeAs layer and the effect of various doping on superconductivity will be discussed.
문의처: 이기봉(054-279-2068, kibong@postech.ac.kr)
"
-2.gif)
Login
