NMR spectroscopy of iron-based superconductors in very high magnetic fields

本研究项目的目的是利用核磁共振波谱技术表征铁基高温超导体在高磁场中的电子基态。这些研究结果将有助于阐明磁波动与超导现象的相关性，以及这些化合物中局部磁序与超导性之间的相互作用。在接近超导相边界的45 T磁场下，研究化学计量学超导体LiFeAs和不同氟掺杂水平的lafeas样品。这样就可以比较超导和正常导电状态下的磁波动谱。此外，将对超导体Sr2VO3FeAs进行压力相关测量，以研究FeAs平面和钙钛矿型夹层中电子态的杂化。该研究项目将在佛罗里达州塔拉哈西的国家高磁场实验室进行。

The aim of this research project is to characterize the electronic ground states of iron-based high-temperature superconductors in high magnetic fields by means of NMR spectroscopy. The results of these studies will help to clarify the relevance of magnetic fluctuations for the appearance of superconductivity as well as the interplay between local magnetic order and superconductivity in these compounds. The stoichiometric superconductor LiFeAs as well as samples of LaOFeAs with different fluorine doping levels will be investigated in magnetic fields up to 45 T, close to the superconducting phase boundary. This allows a comparison of the magnetic fluctuation spectra in the superconducting and normal conducting state. Further, pressure-dependent measurements on the superconductor Sr2VO3FeAs will be performed in order to study the hybridization of electronic states in the FeAs planes and the perovskite-type interlayers. The research project will be conducted at the National High Magnetic Field Laboratory in Tallahassee, Florida.