The key of optimizing quantum reversible logic lies in automatically constructing quantum reversible logic circuits with the minimal quantum cost. This paper constructs a 4 × 4 reversible gate called ZS gate to build quantum full adder. At the same time, a novel reversible No-Wait-Carry adder (or carry skip adder) by using ZSCGPD based on ZS gate with the least cost is also designed. The adder circuit using the proposed ZSCGPD is much better and optimized than other researchers' counterparts both in terms of garbage outputs, number and kind of reversible gates, and quantum cost. In order to show the efficiency of the proposed designs, lower bounds of the reversible carry skip adder in terms of garbage outputs and quantum cost are proposed as well.
The key of optimizing quantum reversible logic lies in automatically constructing quantum reversible logic circuits with the minimal quantum cost. This paper constructs a 4 × 4 reversible gate called ZS gate to build quantum full adder. At the same time, a novel reversible No-Wait-Carry adder (or carry skip adder) by using ZSCGPD based on ZS gate with the least cost is also designed. The adder circuit using the proposed ZSCGPD is much better and optimized than other researchers' counterparts both in terms of garbage outputs, number and kind of reversible gates, and quantum cost. In order to show the efficiency of the proposed designs, lower bounds of the reversible carry skip adder in terms of garbage outputs and quantum cost are proposed as well.
Reversible logic is one of the emerging technologies having promising applications in quantum computing. In this work, we present new design of the reversible BCD adder that has been primarily optimized for the number of ancilla input bits and the number of garbage outputs. The number of ancilla input bits and the garbage outputs is primarily considered as an optimization criteria as it is extremely difficult to realize a quantum computer with many qubits. As the optimization of ancilla input bits and the garbage outputs may degrade the design in terms of the quantum cost and the delay, thus the quantum cost and the delay parameters are also considered for optimization with primary focus towards the optimization of the number of ancilla input bits and the garbage outputs. Firstly, we propose a new design of the reversible ripple carry adder having the input carry Co and is designed with no ancilla input bits. The proposed reversible ripple carry adder design with no ancilla input bits has less quantum cost and the logic depth (delay) compared to its existing counterparts. The existing reversible Peres gate and a new reversible gate called the TR gate is efficiently utilized to improve the quantum cost and the delay of the reversible ripple carry adder. The improved quantum design of the TR gate is also illustrated. Finally, the reversible design of the BCD adder is presented which is based on a 4 bit reversible binary adder to add the BCD number, and finally the conversion of the binary result to the BCD format using a reversible binary to BCD converter.
Reversible logic circuits have received emerging attentions in recent years. Reversible logic is widely applied in some new technical fields, such as quantum computing, nanocomputing and optical computing and so on. In this paper, three fault tolerant gates are proposed, ZPL gate, ZQC gate and ZC gate. By using the proposed gates, fault tolerant quantum and reversible BCD adder and skip carry BCD adder are designed, which overcome the limitations of the existing methods. The proposed reversible BCD adders have also parity-preserving property. They are better than the existing counterparts, especially in the quantum cost. Proposed designs have been compared with existing designs with respect to the number of gates, number of garbage outputs and quantum cost.
Reversible logic is gaining significance in the context of emerging technologies such as quantum computing since reversible circuits do not lose information during computation and there is one-to-one mapping between the inputs and outputs. In this work, we present a class of new designs for reversible binary and BCD adder circuits. The proposed designs are primarily optimized for the number of ancilla inputs and the number of garbage outputs and are designed for possible best values for the quantum cost and delay. In reversible circuits, in addition to the primary inputs, some constant input bits are used to realize different logic functions which are referred to as ancilla inputs and are overheads that need to be reduced. Further, the garbage outputs which do not contribute to any useful computations but are needed to maintain reversibility are also overheads that need to be reduced in reversible designs. First, we propose two new designs for the reversible ripple carry adder: (i) one with no input carry c 0 and no ancilla input bits, and (ii) one with input carry c 0 and no ancilla input bits. The proposed reversible ripple carry adder designs with no ancilla input bits have less quantum cost and logic depth (delay) compared to their existing counterparts in the literature. In these designs, the quantum cost and delay are reduced by deriving designs based on the reversible Peres gate and the TR gate. Next, four new designs for the reversible BCD adder are presented based on the following two approaches: (i) the addition is performed in binary mode and correction is applied to convert to BCD when required through detection and correction, and (ii) the addition is performed in binary mode and the result is always converted using a binary to BCD converter. The proposed reversible binary and BCD adders can be applied in a wide variety of digital signal processing applications and constitute important design components of reversible computing.
Reversible logic circuits have received significant attention in quantum computing, low power CMOS design, optical information processing, DNA computing, bioinformatics, and nanotechnology. This paper presents two new 4 × 4 bit reversible multiplier designs which have lower hardware complexity, less garbage bits, less quantum cost and less constant inputs than previous ones, and can be generalized to construct efficient reversible n × n bit multipliers. An implementation of reversible HNG is also presented. This implementation shows that the full adder design using HNG is one of the best designs in term of quantum cost. An implementation of MKG is also presented in order to have a fair comparison between our proposed reversible multiplier designs and the existing counterparts. The proposed reversible multipliers are optimized in terms of quantum cost, number of constant inputs, number of garbage outputs and hardware complexity. They can be used to construct more complex systems in nanotechnology.
Background/Objectives: The objective is to reduce the Quantum Cost (QC), Garbage Output (GO) and Gate Counts in the design of the adder by incorporating the Novel Reversible Gates. Methods/Statistical Analysis: In recent day’s energy dissipation is the major complex problem in circuit designing in order to recede this problem the reversible logic is employed, where the input vectors can be derived from the output vectors and from the output vectors the input vectors can be procured. Using this technique the Quantum Cost, Garbage Outputs and Gate Counts of the design is reduced. Findings: Based on the technique of reversible logic a novel reversible Gates is proposed from that the novel reversible adders have been designed. The novel reversible gates satisfy the property of reversibility and universality which shows the uniqueness of the proposed gates. The comparative analysis have been made with the existing work, the proposed work shows a significant improvement in the design optimization parameters. Application/Improvements: The proposed structures can be employed in the ALU design and in Floating Point Multiplier design. The comparative analysis shows that Number of Gates, Garbage Outputs and Quantum Cost is minimum for the proposed gate based structure rather than conventional one Keywords: Garbage Outputs (GO), QCA, Quantum Cost (QC), Reversibility, Reversible Logic, Universality.
Within this paper, the authors introduce a new cost optimized quantum Binary-Coded Decimal (BCD) adder circuit that utilizes reversible gates as its building blocks. The newly proposed quantum BCD adder is specifically constructed with the inclusion of double Peres gates (DPG), Peres gates (PG), BJN gates, Feynman gates (FG), and reversible NOT gates. To bring this idea to life, we undertook the design and implementation of the proposed circuit using the Qiskit simulator provided by the IBM Quantum Computing lab. Our evaluation of the newly optimized BCD adder circuit yielded the following metrics, the quantum cost of 47, the constant input of 8, garbage output of 12, and a delay of 10. When compared to previously reported results, we observed significant improvements in various aspects, with a 25.39% reduction in quantum cost, a 28.57% decrease in constant input, and a 36.84% reduction in garbage output.