PHYSICS/BK21 SEMINAR (08/09/17)
관련링크
본문
"제목: Interface metallicity and superconductivity a universal feature of hetero-interfaces with valence
연사: 임성현 박사[Univ. Wisconsin Milwaukee]
일시: 2008 년 9 월 17 일 15:00-16:00
장소: 물리학과 세미나실(3-201)
ABSTRACT:
Two-dimensional (2D) interfaces of hetero-bonded semiconductors and valence mismatch oxides are studied using highly precise FLAPW method. High mobility metallicity at oxide interface, LaAlO3 /SrTiO3 , has been already reported experimentally [1] , while hetero-bonded semiconductor superlattices, CuCl/Si, GaP/Si, and ZnS/Si, were studied in the search for possible superconductivity at interface systems. In all cases, 2D interface metallicity is wellexhibited, as evidenced by band structures, Fermi surfaces, and charge densities, where all materials are insulators in their bulk. [2] The above superlattices are reminiscence of ``metal-dielectric-metal sandwich structures, one of the candidate geometries for excitonic mediation, proposed by Little [3] and Ginzburg [4]. For this, the electron-phonon coupling is calculated within the crude rigid muffin-tin approximation (RMTA), which predicts TC=0.06~4 K for CuCl/Si case only. Further, our preliminary calculation of the effective Coulomb interaction, Veff =V(q,w)/e(q,w), in CuCl/Si, shows that it is possible to have pairing with purely electronic screening. This indicates a possibility of the excitonic mechanism of superconductivity in layered compounds with interface metallicity.
문의처: 민병일(054-279-2074, bimin@postech.ac.kr)
"
연사: 임성현 박사[Univ. Wisconsin Milwaukee]
일시: 2008 년 9 월 17 일 15:00-16:00
장소: 물리학과 세미나실(3-201)
ABSTRACT:
Two-dimensional (2D) interfaces of hetero-bonded semiconductors and valence mismatch oxides are studied using highly precise FLAPW method. High mobility metallicity at oxide interface, LaAlO3 /SrTiO3 , has been already reported experimentally [1] , while hetero-bonded semiconductor superlattices, CuCl/Si, GaP/Si, and ZnS/Si, were studied in the search for possible superconductivity at interface systems. In all cases, 2D interface metallicity is wellexhibited, as evidenced by band structures, Fermi surfaces, and charge densities, where all materials are insulators in their bulk. [2] The above superlattices are reminiscence of ``metal-dielectric-metal sandwich structures, one of the candidate geometries for excitonic mediation, proposed by Little [3] and Ginzburg [4]. For this, the electron-phonon coupling is calculated within the crude rigid muffin-tin approximation (RMTA), which predicts TC=0.06~4 K for CuCl/Si case only. Further, our preliminary calculation of the effective Coulomb interaction, Veff =V(q,w)/e(q,w), in CuCl/Si, shows that it is possible to have pairing with purely electronic screening. This indicates a possibility of the excitonic mechanism of superconductivity in layered compounds with interface metallicity.
문의처: 민병일(054-279-2074, bimin@postech.ac.kr)
"
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