An efficient design of adder/subtractor circuit using quantum dot cellular automata

In this paper, we propose an efficient adder/subtractor circuit using QCA 3-dot cell. This model is highly proficient to compute both addition and subtraction operations. We also showed here a strong subtractor circuit. Moreover, our new and novel schemes has least number of QCA cells till now. The proposed designs carry out more beneficiary than the present ones, e.g., the proposed 32-bit subtractor circuit improves 73% on QCA cell, 99% on area and the proposed 32-bit adder/subtractor circuit improves 90% on QCA cell, 99% on area than the existing best known one.