Numerical study of turnstile operation in random-multidot-channel field-effect transistor

Abstract

We have numerically studied the single-charge transfer operation in two-dimensional (2D) random-multidot-channel field-effect transistors (FETs) using orthodox theory of the Coulomb blockade phenomenon. The randomness of the multidot structure is reflected in the gate capacitance (Cg) in the equivalent circuit, embodying the dot-size disorder of the realistic devices developed in our laboratory. It was found that “turnstile operation” meaning that individual electron is transferred one by one from the source to the drain with a cycle of an alternating gate voltage can be performed in both random and homogeneous 2D multidot-channel FETs, although their equivalent circuits are significantly different from the ordinary four-junction turnstile device. By increasing the Cg randomness, some devices show that the average gate and drain bias condition (Vg0,Vd) which allows the turnstile operation is more relaxed. Consequently, the random-multidot-channel FET can work as a single-electron turnstile device.