Enhancement of superconducting transition temperature in FeSe electric-double-layer transistor with multivalent ionic liquids
Enhancement of superconducting transition temperature in FeSe electric-double-layer transistor with multivalent ionic liquids
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DOI：
10.1103/physrevmaterials.2.031801
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发表时间：
2018-03-26
影响因子：
3.4
通讯作者：
Tsukazaki, Atsushi
中科院分区：
文献类型：
--
作者：
Miyakawa, Tomoki;Shiogai, Junichi;Tsukazaki, Atsushi
本文报道了利用多价低聚离子液体（ILs）提高FeSe基双电层晶体（FeSe-EDLT）的超导转变温度（Tc）。由二聚阳离子（二价IL）组成的IL使得能够在FeSe掺杂膜的表面上积累大量的电荷，导致即使在相当厚的10 nm FeSe沟道中也诱导富电子传导。FeSe-EDLT中的起始Tc与二价离子液体被提高到接近约50 K的薄极限，这是约7 K的高，在EDLT与常规的单价离子液体。Tc的增强是二价IL的应用的显著效果，除了大的电容之外，假设由几何和/或库仑效应驱动的IL的优选界面形成。本研究结果有力地表明，多价离子液体是控制和改善材料物理性能的有力工具。
We report on an enhancement of the superconducting transition temperature (T-c) of the FeSe-based electric-double-layer transistor (FeSe-EDLT) by applying the multivalent oligomeric ionic liquids (ILs). The IL composed of dimeric cation (divalent IL) enables a large amount of charge accumulation on the surface of the FeSe ultrathin film, resulting in inducing electron-rich conduction even in a rather thick 10 nm FeSe channel. The onset T-c in FeSe-EDLT with the divalent IL is enhanced to be approaching about 50 K at the thin limit, which is about 7 K higher than that in EDLT with conventional monovalent ILs. The enhancement of Tc is a pronounced effect of the application of the divalent IL, in addition to the large capacitance, supposing preferable interface formation of ILs driven by geometric and/or Coulombic effect. The present finding strongly indicates that multivalent ILs are powerful tools for controlling and improving physical properties of materials.