Presenter: Prof. Dong Qian (上海交通大学)
Topic: Magnetic order in single monolayer FeSe/SrTiO3(001) films
Time:
Location: Conference Room G, BLDG 909
Abstract
Single monolayer (ML) FeSe film grown on Nd-doped SrTiO3(001) substrate shows the highest superconducting transition temperature (TC ~ 100 K) among the iron-based superconductors (iron-pnictide), while the TC of bulk FeSe is only ~ 8 K. AFM spin fluctuation was proposed to be crucial in iron-pnictide. Based on spin fluctuation scenario, several proposals have been raised to understand the FeSe/SrTiO3 system. Though bulk FeSe does not show AFM order, calculations proposed that the parent FeSe/SrTiO3 film is AFM and AFM interaction is enhanced in the interface. Experimentally, lacking of directly probe, the magnetic state of FeSe/SrTiO3 films remains mysterious. In this talk, I will present the direct evidences that the parent 1-ML FeSe/SrTiO3 film is AFM. We find that AFM interaction is strongly enhanced in 1-ML FeSe/SrTiO3 film compared with the “isolated” 1-ML film. AFM order disappears and superconductivity appears by electron doping. Our findings provide crucial information to understand the superconducting behavior in FeSe/SrTiO3 films.
Biography
钱冬，1998年复旦大学物理系本科毕业，2003年复旦大学物理系获得博士学位，2003-2009年普林斯顿大学物理系博士后和研究助理，2009年起加入上海交通大学物理与天文系任特别研究员，2015年起
联系人：钟俊 教授
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