JPH0624258B

A field-effect structure, formed on a substrate (20) and comprising a channel (21) with source (22) and drain (23) as well as a gate (25) that is separated from the channel by an insulating layer (24). The channel is made of a high-Tc metal-oxide superconductor, e.g., YBaCuO, having a carrier density of about 10 /cm and a correlation length of about .2 nm. The channel thickness is in the order of 1 nm, it is single crystalline and oriented such that the superconducting behaviour is strongest in the plane parallel to the substrate. With a signal of a few Volt applied to the gate, the entire channel cross-section is depleted of charge carriers whereby the channel resistance can be switched between "zero" (undepleted, superconducting) and "very high" (depleted).