摘要
Superconductivity beyond electron-phonon mechanism is always twisted with magnetism. Based on a new field-effect transistor with solid ion conductor as the gate dielectric(SIC-FET), we successfully achieve an electric-field-controlled phase transition between superconductor and ferromagnetic insulator in(Li,Fe)OHFeSe. A dome-shaped superconducting phase with optimal T_c of 43K is continuously tuned into a ferromagnetic insulating phase, which exhibits an electric-field-controlled quantum critical behavior. The origin of the ferromagnetism is ascribed to the order of the interstitial Fe ions expelled from the(Li,Fe)OH layers by gating-controlled Li injection. These surprising findings offer a unique platform to study the relationship between superconductivity and ferromagnetism in Fe-based superconductors. This work also demonstrates the superior performance of the SIC-FET in regulating physical properties of layered unconventional superconductors.
Superconductivity beyond electron-phonon mechanism is always twisted with magnetism. Based on a new field-effect transistor with solid ion conductor as the gate dielectric(SIC-FET), we successfully achieve an electric-field-controlled phase transition between superconductor and ferromagnetic insulator in(Li,Fe)OHFeSe. A dome-shaped superconducting phase with optimal T_c of 43K is continuously tuned into a ferromagnetic insulating phase, which exhibits an electric-field-controlled quantum critical behavior. The origin of the ferromagnetism is ascribed to the order of the interstitial Fe ions expelled from the(Li,Fe)OH layers by gating-controlled Li injection. These surprising findings offer a unique platform to study the relationship between superconductivity and ferromagnetism in Fe-based superconductors. This work also demonstrates the superior performance of the SIC-FET in regulating physical properties of layered unconventional superconductors.
基金
supported by the National Key R&D Program of China(2017YFA0303001 and 2016YFA0300201)
the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(XDB25010100)
the National Natural Science Foundation of China(11888101 and 11534010)
Science Challenge Project(TZ2016004)
Hefei Science Center CAS(2016HSC-IU001)
