Field effect in multilayered YBaCuO/PrBaCuO devices

A MOSFET-like device with a thin superconducting PrBaCuO/YBaCuO multilayer channel and SiO/sub 2/ gate oxide was built. The effect of electric field applied on the gate was investigated as a function of temperature and drain-source current for different multilayers. It was shown that the critical temperature, as well as the density of the critical current could be enhanced or suppressed depending on the polarity of the gate voltage. The use of a SiO/sub 2/ layer as a gate insulator gives symmetrical characteristics and low losses in the MHz range. A new slow charge transfer effect has been observed at higher temperatures. Field effects on the resistance and on the critical current have been observed for monolayer channels as well as for multilayer structures with up to three (YBaCuO/PrBaCuO) periods. The field effect decreases with an increasing number of periods because of the semiconducting PrBaCuO layers. In these multilayer structures, the observed charge transfer effects could be an electrical way to definitively tune the charge carrier concentration and the transition temperature of very thin films.>