Efficient designs of reversible latches with low quantum cost

Abstract

Reversible computing is one of the most promising technologies in the design of low-power digital circuits, optical information processing, quantum computing, DNA computing, digital signal processing, and nanotechnology. The main purpose of the design of reversible circuits is to reduce the energy consumption that occurs due to the loss of input bits in irreversible circuits. A gate/block is reversible if the number of inputs and the number of outputs are equal and there is one-to-one correspondence between them. Latches are considered as one of the most important digital structures that are widely used as building blocks in the design of sequential circuits. Here, eight new reversible blocks are first offered. Then using some of them, several effective designs of reversible D, T, and J-K latches are proposed. The results of the evaluations indicate that the proposed latches are superior in terms of quantum cost (QC) than previous designs. Moreover, they are very close to or better than the best previous designs in terms of criteria such as gate count (GC), constant inputs (CI), and garbage outputs (GO).