Signal Synchronization in Large Scale Quantum-dot Cellular Automata Circuits

Quantum-dot fabrication is a well-established nanotechnology, which have many applications in many different scientific fields. By placing four quantum-dots on the corners of a square, a cell is formed, in which the digital information can be stored. This cell serves as the structural device of Quantum-dot Cellular Automata (QCA) circuits. After QCA presentation, several digital circuits and systems have been designed and proposed in the literature. However, one of the biggest problems QCA designers have to face to pave the successful design of functional and large scale QCA circuits is signal synchronization. In this paper, a novel approach of the aforementioned problem is presented. This approach is inspired by the well known computational problem of Firing Squad Synchronization (FSS). FSS problem has many similarities with large scale QCA circuits synchronization problem. In addition, FSS problem has been studied by many researchers and many efficient solutions have been proposed in the literature.