Design and Implementation of Novel Efficient Full Adder/Subtractor Circuits Based on Quantum-Dot Cellular Automata Technology

Abstract

One of the emerging technologies at the nanoscale level is the Quantum-Dot Cellular Automata (QCA) technology, which is a potential alternative to conventional CMOS technology due to its high speed, low power consumption, low latency, and possible implementation at the atomic and molecular levels. Adders are one of the most basic digital computing circuits and one of the main building blocks of VLSI systems, such as various microprocessors and processors. Many research studies have been focusing on computable digital computing circuits. The design of a Full Adder/Subtractor (FA/S), a composite and computing circuit, performing both the addition and the subtraction processes, is of particular importance. This paper implements three new Full Adder/Subtractor circuits with the lowest number of cells, lowest area, lowest latency, and a coplanar (single-layer) circuit design, as was shown by comparing the results obtained with those of the best previous works on this topic.

Novel Reversible Comparator Design in Quantum Dot-Cellular Automata with Power Dissipation Analysis

“…Circuits are designed and implemented in QCA, based on QCA cells. As mentioned in QCA technology, communication and calculations are achieved via the interaction of coulombic repulsion of QCA cells and influence on neighboring cells, in order to influence the electrons enclosed in each cell, thus transmitting and spreading information [7]. As a result, based on the interaction of coulombic repulsion, QCA wire is used for the communication required in QCA, and digital gates are used to create its computing circuits.…”

“…As a result, based on the interaction of coulombic repulsion, QCA wire is used for the communication required in QCA, and digital gates are used to create its computing circuits. Figure 1a shows the QCA 90-degree cell in both logical 0 and 1 modes [7][8][9][10]. Coulombic energy is used between neighboring cells for data transfer and QCA operations.…”

“…Another type of coplanar wire is known as 45-degree wire. This wire is created by using a 45-degree cell and putting this type of cell together [7]. Figure 1c shows the QCA 45-degree cell.…”

“…This technology is different than conventional technology, and it does not use any current or voltage to transmit information. Rather, a coulombic relation the QCA cells created paths for propagation and the transmission of information; these paths are called QCA wires [7]. On the other hand, one of the basic blocks in digital logic design is comparators, which compare two numbers.…”

Design and Analysis of Fault-Tolerant 1:2 Demultiplexer Using Quantum-Dot Cellular Automata Nano-Technology

“…The requests for high-velocity operation with down-energy utilization and leakage current, along with the scaling restrictions of CMOS constructs, have forced investigators to look for substitution technologies [2]. When the component size reduces, efficiency enhances; thus, a direct connection exists between efficiency and compression [3]. Quantum-dot Cellular Automata (QCA) is one of the most hopeful nano-scale technologies that has been presented as a transistor-less paradigm [4,5].…”