Anomalous correlation effects and unique phase diagram of electron-doped FeSe revealed by photoemission spectroscopyстатья
Статья опубликована в высокорейтинговом журнале
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Дата последнего поиска статьи во внешних источниках: 20 апреля 2016 г.
Аннотация:FeSe layer-based superconductors exhibit exotic and distinctive properties. The undoped FeSe
shows nematicity and superconductivity, while the heavily electron-doped KxFe2 ySe2 and
single-layer FeSe/SrTiO3 possess high superconducting transition temperatures that pose
theoretical challenges. However, a comprehensive study on the doping dependence of an
FeSe layer-based superconductor is still lacking due to the lack of a clean means of doping
control. Through angle-resolved photoemission spectroscopy studies on K-dosed thick FeSe
films and FeSe0.93S0.07 bulk crystals, here we reveal the internal connections between these
two types of FeSe-based superconductors, and obtain superconductivity below B46 K in an
FeSe layer under electron doping without interfacial effects. Moreover, we discover an exotic
phase diagram of FeSe with electron doping, including a nematic phase, a superconducting
dome, a correlation-driven insulating phase and a metallic phase. Such an anomalous phase
diagram unveils the remarkable complexity, and highlights the importance of correlations in
FeSe layer-based superconductors.