Coupled quantum well devices (cqwd) containing two or more direct selective contacts and methods of making same

Abstract

The present invention relates to a device structure that contains two or more conducting layers, two peripheral insulating layers, one or more intermediate insulating layers, and two or more conductive contacts. The two or more conducting layers are sandwiched between the two peripheral insulating layers, and they are spaced apart by the intermediate insulating layers to form two or more quantum wells. Each of the conductive contacts is directly and selectively connected with one of the conducting layers, so the individual quantum wells can be selectively accessed through the conductive contacts. Such a device structure preferably contains a coupled quantum well devices having two or more quantum wells that can be coupled together by inter-well tunneling effect at degenerate energy levels. More preferably, the device structure contains a memory cell having three quantum wells that can be arranged and constructed to define two different memory states.