De Simoni Giorgio, Paolucci Federico, Puglia Claudio, Giazotto Francesco
NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore , I-56127 Pisa , Italy.
INFN Sezione di Pisa , Largo Bruno Pontecorvo 3 , 56127 Pisa , Italy.
ACS Nano. 2019 Jul 23;13(7):7871-7876. doi: 10.1021/acsnano.9b02209. Epub 2019 Jun 20.
We demonstrate proximity-based mesoscopic superconductor-normal metal-superconductor (SNS) field-effect controlled Josephson transistors (SNS-FETs) and show their full characterization from the critical temperature down to 50 mK in the presence of both electric and magnetic fields. The ability of a static electric field-applied by means of a lateral gate electrode-to suppress the critical current in a proximity-induced superconductor is proven for both positive and negative gate voltage values. reached typically about one-third of its initial value, saturating at high gate voltages. The transconductance of our SNS-FETs obtains values as high as 100 nA/V at 100 mK. On the fundamental physics side, our results suggest that the mechanism at the basis of the observed phenomenon is quite general and does not rely on the existence of a true pairing potential, but rather the presence of superconducting correlations is enough for the effect to occur. On the technological side, our findings widen the family of materials available for the implementation of all-metallic field-effect transistors to proximity-induced superconductors.
我们展示了基于近邻效应的介观超导-正常金属-超导（SNS）场效应控制约瑟夫森晶体管（SNS-FET），并在电场和磁场存在的情况下，展示了它们从临界温度到50 mK的完整特性。通过横向栅电极施加的静电场抑制近邻诱导超导体中的临界电流的能力，在正栅极电压值和负栅极电压值下均得到了证实。临界电流通常降至其初始值的约三分之一，在高栅极电压下达到饱和。我们的SNS-FET在100 mK时的跨导高达100 nA/V。在基础物理学方面，我们的结果表明，所观察到的现象背后的机制相当普遍，并不依赖于真正配对势的存在，而是超导相关性的存在就足以使该效应发生。在技术方面，我们的发现将可用于实现全金属场效应晶体管的材料家族扩展到了近邻诱导超导体。
