Effect of temperature and kink energy in multilevel digital circuit using Quantum dot cellular automata

Quantum-dot Cellular Automata (QCA) is a paradigm for low power, high speed computation technique in the field of nanoscience. Till today three types of QCA structures are discussed among them magnetic and molecular QCA operates at room temperature but the metallic dot QCA structure operates at a very low temperature at around absolute zero degree Kelvin. In this paper we comprehended that if the spacing between two consecutive cells in a metallic dot QCA is reduced lower than 2nm then the operating temperature can be enhanced up to 12 degree Kelvin. Instead of using only one majority gate we have used multi-input level shifter circuit where four majority gates are used and the output depend on all the inputs and the majority gates operation. According to QCADesigner tool, 2nm spacing between two consecutive cell is taken as standard for any circuit. Multi input level shifter circuit based on Quantum-dot Cellular Automata (QCA) is working at increased temperature with decreasing cell space.