logo

korean english

게시판

Home > 게시판 > 세미나

다음과 같이 세미나 모임을 개최합니다. 많은 참석 부탁합니다. 참석자에게는 점심을 제공합니다.


 2015/ 4/ 25/ 토/


연사: 박두선 교수 (성균관대)

시간: 오전 10:30-12:00

장소: 삼성학술정보관 7층 Creative Learning Room

제목: Controlling superconductivity by tunable quantum critical points

초록:The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.


연사: 김기석 교수 (포항공대)

시간: 오후 1:00-4:00

장소: 물리학과 라운지 세미나실 (31동 2층)

제목: Emergent gauge fields and their nonperturbative effects in correlated electrons

초록: The history of modern condensed matter physics may be regarded as the competition and reconciliation between Stoner's and Anderson's physical pictures, where the former is based on momentum-space descriptions focusing on long wave-length fluctuations while the latter is based on real-space physics emphasizing emergent localized excitations. In particular, these two view points compete with each other in various nonperturbative phenomena, which range from the problem of high Tc superconductivity, quantum spin liquids in organic materials and frustrated spin systems, heavy-fermion quantum criticality, metal-insulator transitions in correlated electron systems such as doped silicons and two-dimensional electron systems, the fractional quantum Hall effect, to the recently discussed Fe-based superconductors. An approach to reconcile these competing frameworks is to introduce topologically nontrivial excitations into the Stoner's description, which appear to be localized in either space or time and sometimes both, where scattering between itinerant electrons and topological excitations such as skyrmions, vortices, various forms of instantons, emergent magnetic monopoles, and etc. may catch nonperturbative local physics beyond the Stoner's paradigm. In this review article we discuss nonperturbative effects of topological excitations on dynamics of correlated electrons.


번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1079610
427 <2/16>Hamiltonian formalism 2011.02.11 90282
426 <Oct.30(Wed.)> 왼손과 오른손, 기본 입자와 끈 2019.10.24 90176
425 <4/16>같은 곳을 바라보는 다른 시선 2010.04.09 90145
424 2015학년도 2학기 콜로퀴움 일정 2015.08.06 90114
423 <1/14>Dark Matter signals from PAMELA and ATIC 2009.01.12 90069
422 <3/12> Where, when and how atomic nuclei were cooked in universe? 2014.03.07 89909
421 <6/9> Status and Prospects of Big Science in Korea 2006.06.05 89754
420 <2/15> Perturbation during Inflation 2011.02.11 89715
419 <4/30> Characterization of Molecular Transistors and Organic Memory Devices 2010.04.15 89688
418 <4/3>Enhanced emission rate from a single quantum well using surface plasmon 2009.03.31 89677
417 <11/23> How statistical physics contributes to Internet world: perspectives, methods and applications 2011.11.15 89326
416 <6/19> Kohn's theorem and non-relativistic symmetry 2012.06.15 89196
415 콜로퀴움 강연 일정표 2006.02.21 89165
414 <6/21> Nuclear Astrophysics in Effective Field Theories 2012.06.20 89076
413 <3/26>A perturbative & non-perturbative test of ABJM model 2009.03.19 89040
412 <7/21> Next generation cryogenic free 1.5T MgB2-magnet based MRI 2010.07.20 89008
411 <7월27일>Correlated topological phases in 3D complex oxides via Green's functions 2012.07.27 89001
410 <11/4 오전 10:30> Quantum transport through topological-metal strip 2013.10.23 88620
409 <10/17> The Interface Induced Magnetism 2012.10.11 88482
408 <12/7> Optical Antennas 2011.11.30 88409