Design of Shift Registers in QCA Technology

This study introduces an innovative approach to design highly efficient circuits at the nanoscale, employing Quantum-dot Cellular Automata (QCA). QCA is a transistor less technology which employs quantum mechanical principles to carry out digital computations and implement area efficient, low power consuming digital circuits. The shift register which is a versatile digital circuit, can be used in applications including data storage, signal processing, and communication systems. By utilizing D flip-flops, a diverse array of shift registers can be constructed, offering to scale them up to accommodate n bits. In this work, 4 bit SIPO and PIPO shift registers are designed. The designs proposed in this work undergo validation of their operations through the use of the QCA Designer tool and compared with the existing designs in CMOS Technology in area which is found to be reduced by 99.7% and 99.9% for SIPO and PIPO Shift register respectively.