Efficient QCA design of single-bit and multi-bit subtractors

The design of digital circuits in Quantum Dot Cellular Automata (QCA) has been of active interest in the last decade. While there are many proposals for design of adders, work on subtractors is limited. This paper presents efficient QCA designs of single-bit and multi-bit subtractors. The designs are based on new results on majority logic. Simulations in QCADesigner are presented. The complexity of the proposed designs in terms of cell count and area are also given. © 2013 IEEE.