logo

korean english

게시판

Home > 게시판 > 세미나

Brookhaven National Laboratory의 Christopher Homes교수님을 초청하여 아래와 같이 세미나를 개최합니다.

학과 구성원 여러분의 많은 참석을 부탁 드립니다. 

 

아 래

   

제목: Optical properties of iron-based conductors and superconductors

 

연사: Prof. Christopher Homes (Condensed Matter Physics and Materials Science Dept., Brookhaven National Laboratory) 

 

일시: 2014. 4. 21(월) 오후 2:00 ~ 4:00

  

장소: 삼성학술정보관 7층 Creative learning room

 

초록: In the high-temperature cuprate superconductors, only a single band is observed at the Fermi level; as a result the optical conductivity may be modeled using a single free-carrier component.  In a simple metal the Drude model usually sufficient; however, electronic correlations and electron-boson coupling in the cuprates require a more generalized form in which the scattering rate and the effective mass are both frequency dependent [1].  The iron-based conductors and superconductors are multiband materials with several bands crossing the Fermi level, resulting in multiple hole and electron pockets at the center and corners of the Brillouin zone, respectively [2].  The presence of multiple bands requires, at a minimum, a “two-Drude” model in which the electron and hole pockets are treated as separate contributions [3]. In general, the two-Drude approach reveals: (i) a strong component associated with the hole pocket with a large scattering rate (nearly incoherent transport) that is essentially temperature independent; (ii) a weaker component associated with the electron pocket whose scattering rate has a strong temperature dependence.  Some recent results using this approach in the pnictide materials BaFe2As2 (TN~138 K) and Ba0.6K0.4Fe2As2 (Tc~38 K) [4] will be discussed, as well as some preliminary findings the iron-chalcogenide systems, Fe1+Te (TN~68 K) and FeTe0.55Se0.45 (Tc~14 K) [5].

*This work done in collaboration with Yaomin Dai, Qiang Li, Jinsheng Wen, Zhijun Xu, Genda Gu, Ricardo Lobo, and Ana Akrap; work supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Contract No. DE-AC02-98CH10886.

[1] A. V. Puchkov, D. N. Basov, and T. Timusk, J. Phys.: Condens. Matter 8, 10049 (1996).
[2] S. Raghu et al., Phys. Rev. B 77, 220503(R) (2008).
[3] D. Wu et al., Phys. Rev. B 81, 100512 (2010).
[4] Y. M. Dai et al., Phys. Rev. Lett. 111, 117001 (2013).
[5] C. C. Homes et al., Phys. Rev. B 81, 180508(R) (2010).
 

번호 제목 날짜 조회 수
공지 <12/8(Thu.) 11:00am>노벨상 소개 강연 - 2016년 노벨 물리학상: 위상 응집 물리의 탄생 2016.11.28 1060576
182 <3/31> ZnO nanorod heterostructures and nanodevices 2006.03.27 117303
181 <3/24> 복잡계 네트워크와 경제물리학(Complex Networks and Econo-Physics) 2006.03.20 81453
180 콜로퀴움 강연 일정표 2006.02.21 86633
179 콜로퀴움입니다. 2005.12.29 77336
178 콜로퀴움 게시판입니다. 2011.02.28 79305
177 <5/12(월)> Nanoscale probing of electrochemical phenomena and ionic dynamics by scanning probe microscopy 2014.05.07 95399
» <4/21(월) 오후 2시> Optical properties of iron-based conductors and superconductors 2014.04.15 74789
175 <4/18(금)> 양자물질초전도체창의연구소 초청 세미나 2014.04.15 165412
174 <3/28> A global financial settlement network and its cascading effects 2014.03.26 60304
173 <1/2> MYRRHA Project (EU 4세대 원전 사업) 2013.12.30 62654
172 <12/30> Correlation between Raman scattering and conductance in a molecular junction 2013.12.23 69413
171 <12/26> Emergent Physics in 3D Correlated Topological Semimetals file 2013.12.20 132212
170 <12/30> Dirac vs. Weyl in topological insulators: Adler-Bell-Jackiw anomaly in transport phenomena 2013.12.16 115217
169 <11/11> Revealing magnetism of nanoislands with quantitative insights into spin-polarized scanning tunneling spectroscopy 2013.11.05 93601
168 <11/5(화)> 특별세미나 개최 안내 2013.11.01 225361
167 <11/4 오후 3:30> Surface impurity induced self energy in bulk on a topological insulator 2013.10.23 88238
166 <11/4 오전 10:30> Quantum transport through topological-metal strip 2013.10.23 83160
165 <10/28> Magneto-electric response of multiferroic chiral magnets 2013.10.21 73414
164 <8/21(수)> 고온 초전도 특별세미나 2013.08.21 75978
163 <8/20> Radioprotection effect and anti-tumor immunity by TCM-EF in mice 2013.08.21 161186