Electric-field-induced superconductivity in an insulator
Electric-field-induced superconductivity in an insulator
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DOI：
10.1038/nmat2298
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发表时间：
2008-11-01
期刊：
影响因子：
41.2
通讯作者：
Kawasaki, M.
中科院分区：
文献类型：
--
作者：
Ueno, K.;Nakamura, S.;Kawasaki, M.
长期以来，电场控制载流子密度一直是调节凝聚态物质物理性质、探索现代半导体工业的关键技术。最大的挑战之一是增加可获得的最大载流子密度，以便我们能够在场效应晶体管几何结构中诱导超导。然而，到目前为止，由于介质击穿，此类实验仅限于对原始导电样品中的临界温度进行调制(1-4)。在这里，我们报道了在有机电解液中使用双电层栅极在绝缘体中的电场感应超导(5)。通过将高达3.5V的栅极电压施加到原始的SrTiO_3单晶沟道，将薄片载流子密度从零提高到10(14)cm(-2)。在0.4K的临界温度以下出现了一个二维超导态，与化学掺杂的大块晶体的最大值相当(6)，这表明这种方法在寻找前所未有的超导态方面是有希望的。
Electric field control of charge carrier density has long been a key technology to tune the physical properties of condensed matter, exploring the modern semiconductor industry. One of the big challenges is to increase the maximum attainable carrier density so that we can induce superconductivity in field-effect-transistor geometry. However, such experiments have so far been limited to modulation of the critical temperature in originally conducting samples because of dielectric breakdown(1-4). Here we report electric-field-induced superconductivity in an insulator by using an electric-double-layer gating in an organic electrolyte(5). Sheet carrier density was enhanced from zero to 10(14) cm(-2) by applying a gate voltage of up to 3.5V to a pristine SrTiO3 single-crystal channel. A two-dimensional superconducting state emerged below a critical temperature of 0.4 K, comparable to the maximum value for chemically doped bulk crystals(6), indicating this method as promising for searching for unprecedented superconducting states.