korean english


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 1078816
386 <Aug. 4(Wed.)>Electronic Properties of Mixed-dimensional 2D/3D Heterostructures 2021.08.04 79279
385 <10/26> 빛으로 보는 세상 2011.10.17 79591
384 <11/27> N=4,5,6,8 superconformal Chern-Simons theory 2008.11.25 79612
383 <11/19(수)> 3D topological insulators with magnetic impurities 2014.11.13 79688
382 <9/26> High Energy Physics as e-Science 2008.09.22 79703
381 2008학년도 1학기 물리세미나1 강의계획서 2008.03.18 79796
380 콜로퀴움 게시판입니다. 2011.02.28 79818
379 <6/13> Efficient hybrid organic-inorganic light emitting diodes by surface modification of metal oxides 2012.06.01 79880
378 <11/17>의학에서의 치료음향 Therapeutic Sound in Medicine 2006.11.15 79884
377 <April. 5 (Wed.) 4:30 PM>Majorana quasiparticles emergent in Kitaev quantum magnets 2017.03.31 79958
376 2011학년도 1학기 콜로퀴엄 일정 안내 2011.01.25 79991
375 <11/30> 기능성 산화물의 현황과 응용 2011.11.24 80143
374 <5/9> Gravity dual of (Non-)Fermi Liquids from Entanglement Entropy 2012.05.07 80145
373 <10/18(Thu.) 1:30pm>Machine Learning Approaches for Solving Physics Problems: Usability of Experimental Data 2018.10.15 80200
372 <3/27> The Born series for S-wave spin-quartet neutron-deuteron scattering at small cutoff values. 2013.03.25 80367
371 <11/28> 건국 100주년을 대비하는 과학청년의 자세 2008.11.25 80367
370 <9/22> 진실 vs. 거짓, 도대체 과학이란 무엇인가? 2006.09.18 80394
369 <5/26> Nanomagnetic Materials and First Principles Approach 2006.05.22 80432
368 <May.2(Wed.) 4:30 PM> Machine learning and statistical physics 2018.04.23 80574
367 <4/2> 다중벽탄소나노튜브를 이용한 AFM 탐침 개발과 응용 2010.03.29 80613