Puglia Claudio, De Simoni Giorgio, Giazotto Francesco
Department of Physics, University of Pisa, Largo Pontecorvo 3, I-56127 Pisa, Italy.
NEST, Instituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa, Italy.
Materials (Basel). 2021 Mar 5;14(5):1243. doi: 10.3390/ma14051243.
The possibility to tune, through the application of a control gate voltage, the superconducting properties of mesoscopic devices based on Bardeen-Cooper-Schrieffer metals was recently demonstrated. Despite the extensive experimental evidence obtained on different materials and geometries, a description of the microscopic mechanism at the basis of such an unconventional effect has not been provided yet. This work discusses the technological potential of gate control of superconductivity in metallic superconductors and revises the experimental results, which provide information regarding a possible thermal origin of the effect: first, we review experiments performed on high-critical-temperature elemental superconductors (niobium and vanadium) and show how devices based on these materials can be exploited to realize basic electronic tools, such as a half-wave rectifier. Second, we discuss the origin of the gating effect by showing gate-driven suppression of the supercurrent in a suspended titanium wire and by providing a comparison between thermal and electric switching current probability distributions. Furthermore, we discuss the cold field-emission of electrons from the gate employing finite element simulations and compare the results with experimental data. In our view, the presented data provide a strong indication regarding the unlikelihood of the thermal origin of the gating effect.
最近已证明，通过施加控制栅极电压来调节基于巴丁 - 库珀 - 施里弗金属的介观器件的超导特性是可行的。尽管在不同材料和几何结构上获得了大量实验证据，但尚未提供关于这种非常规效应背后微观机制的描述。这项工作讨论了金属超导体中超导性的栅极控制的技术潜力，并对实验结果进行了修正，这些结果提供了有关该效应可能的热起源的信息：首先，我们回顾了在高临界温度元素超导体（铌和钒）上进行的实验，并展示了如何利用基于这些材料的器件来实现基本电子工具，如半波整流器。其次，我们通过展示悬浮钛丝中超电流的栅极驱动抑制，并通过比较热开关电流和电开关电流概率分布来讨论栅极效应的起源。此外，我们利用有限元模拟讨论了来自栅极的电子冷场发射，并将结果与实验数据进行比较。我们认为，所呈现的数据有力地表明了栅极效应热起源的可能性不大。
