Charge transport in superconducting heterostructures MoRe–Si(W)–MoRe with hybrid semiconductor barrier with metal nanoclusters
V.E. Shaternik1, A.P. Shapovalov1,2, and O.Yu. Suvorov1
1G.V. Kurdyumov Institute for Metal Physics, NAS of Ukraine, 36 Academician Vernadsky Boulevard, Kyiv 03680, Ukraine
2V. Bakul Institute for Superhard Materials, NAS of Ukraine, 2, Avtozavodskaya Str., Kiev, 04074, Ukraine
Received February 13, 2017
Thin-film heterostructures MoRe–Si(W)–MoRe consisting of superconducting electrodes (molybdenum-rhenium alloy) and a hybrid semiconductor tunneling barrier of nanoscale silicon layer with tungsten nanoclusters have been fabricated and experimentally studied. Current-voltage characteristics of the heterostructures have been measured for a wide volt-age range from –900 to 900 mV and at temperatures ranging from 4,2 to 8 K, under the influence of magnetic fields and microwave irradiation. From the authors point of view the temperature dependencies of the superconducting critical current and normal-state resistance of the heterostructures could point at the feasibility of the Coulomb blockade regime, resonant tunneling and resonant-percolation transport mechanism in them depending on the tungsten content in the hybrid barriers and the applied bias voltage. The measured characteristics give us a possibility to assume that if the superconducting current is higher than some critical one the phase-slipping centers of the superconducting order parameter appears in the tungsten clusters.