Quantum Cellular Automaton Device Using the Image Charge Effect

Abstract

A quantum cellular automaton (QCA) device that uses the image charge effect is proposed. This image-charge QCA device is constructed from many unit cells on a metal substrate covered with an insulator layer. Each unit cell consists of four quantum dots and two excess electrons. Two positive image charges in the metal substrate maintain the charge neutrality of each cell. The distance between two neighboring cells is designed to allow intercellular electron tunneling. The image-charge QCA cell can overcome two basic problems: establishing charge neutrality in each cell and loading electrons easily and precisely. We designed signal-transmission and elemental logic gate circuits using these image-charge QCA cells, and simulated operation of the circuits by computer simulation. It is demonstrated that the image-charge QCA circuits can perform signal transmission and elemental logic operations and that electrons (two per cell) can be easily loaded into the image-charge QCA circuits.