logo

korean english

게시판

Home > 게시판 > 세미나

아래와 같이 콜로퀴움을 개최하오니 많이 참석해 주시기 바랍니다.

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

 

아 래

 

제목: Electron phonon coupling effect in 4d transition metal oxide magnetism

 

연사: 김   창   영 교수님 (연세대학교)

 

일시: 2011년 6월 1(수) 오후4:30

 

장소: e+첨단강의실 (31214호실)

 

초록:

Spin triplet superconductivity observed in Sr2RuO4 triggered the research on 4d transition metal oxides. The triplet pairing for the superconductivity in Sr2RuO4 is theoretically suggested that the pairing is mediated by the exchange of ferromagnetic (FM) fluctuation. However, absence of ferromagnetic fluctuation and repeated observations of incommensurate antiferromagnetic (AFM) fluctuation from inelastic neutron scattering indicate that a better understanding of magnetism is needed.

Related to the issue in Sr2RuO4 is the magnetism in Ca2-xSrxRuO4 (CSRO) for which RuO6 octahedra are rotated. While density functional calculations predict FM ground state for systems with rotated RuO6, AFM ordering has recently been observed in the magnetic susceptibility data from CSRO. As the theoretically predicted FM ground state of RuO6 system is known to be closely related to the pairing mechanism of Sr2RuO4 spin-triplet superconductivity, AFM ordering observed in CSRO raises questions about the FM fluctuation mediated spin triplet superconductivity in Sr2RuO4.

For a better understanding of the magnetic phase diagram, we performed high-resolution angle resolved photoemission on Sr2RuO4 as well as on a related material Sr2-xLaxRhO4. ARPES results from systems with rotated RuO6 octahedral (surface states of Sr2RuO4 and Sr2-xLaxRhO4) show strong kink features in the band dispersion. The kink structure causes enhanced van Hov singularity and increases the density of states at the Fermi level, which in turn affects the magnetism. The origin of kink is found to be from the electrn phonon coupling. By comparing the magnetic properties and electronic structures of CSRO, SLRhO and SLRuO, I will try to explain the role of electron-phonon coupling in the magnetism of 4d transition metal oxides.

번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1032947
602 <11/5> Modified nucleic acid systems for biomedical applications 2010.11.01 110648
601 <Nov.13(Fri) 16:00> Kondo screening in mixed valence and heavy fermion compounds and the signatures of Nozieres’ exhaustion 2015.11.04 110643
600 <10/28>Grazing Incidence X-ray Diffraction and Surface X-ray Scattering Study of Hematite (α-Fe2O3) Nano-cube 2011.10.26 110590
599 <10/17> Graphitic Carbon Nanostructures 2008.10.27 110445
598 <3/19> Bioconjugates of nanomaterials for biochip & biosensor applications 2010.03.16 110046
597 <1/28> Steps towards a non-relativistic AdS/CFT 2010.01.25 109559
596 <3/31> ZnO nanorod heterostructures and nanodevices 2006.03.27 109523
595 <8/5>Brane superpotential via local Calabi-Yau spaces 2009.08.03 109436
594 2018학년도 1학기 콜로퀴움 일정 2018.01.03 108887
593 <4/21> Experimental and Observational Astrophysics in the Infrared Wavebands 2009.04.17 108782
592 <5/14> Search for exotic materials: strongly correlated electron system 2010.05.10 108424
591 <5/21> Magnetism and Superconductivity 2014.05.14 107053
590 2017학년도 2학기 콜로퀴움 일정 2017.07.04 105821
589 <3/26> Fractional Hall Physics of Epitaxial Graphene: 2010.03.19 105262
588 2014학년도 2학기 콜로퀴움 일정 2014.09.11 104854
587 <3/12(화)>물리학과 특별초청강연 개최 안내 2013.03.04 104720
586 <7/28> NQR/NMR study on a single crystal of LiFeAs 2010.07.20 104133
585 <10/15> How can population pyramids be used to explore the past? 2010.10.14 103754
584 <4/30(화)> DC (DNA Curtains) and AC (Actin Curtains) in single-molecule biophysics 2013.04.11 103501
583 <6/8> 액체금속 및 물의 과냉각 현상과 국소구조와의 관계 : 정전기 공중부양 기술 및 dynamic diamond anvil cell 2011.06.07 103468