Nanoarchitecture of Quantum-Dot Cellular Automata (QCA) Using Small Area for Digital Circuits

Abstract

Novel digital technologies always lead to high density and very low power consumption. One of these concepts-quantum-dot cellular automata (QCA), which is one of the new emerging nanotechnologies, is based on Coulomb repulsion. This chapter presents a novel design of 2-input Exclusive-NOR (XNOR)/Exclusive-OR (XOR) gates with 3-input Exclusive-NOR (XNOR) gates which are composed of 10 cells on 0.006 μm 2 of area. A novel architecture of 3-input Exclusive-OR (XOR) gate is defined by 12 cells on 0.008 μm 2 of area. The proposed design of 2-input XOR/XNOR gate structures provide less area and low complexity than the best reported design. The simulation results of proposed designs have been achieved using QCA Designer tool version 2.0.3.

Designs of Level-Sensitive T Flip-Flops and Polar Encoders Based on Two XOR/XNOR Gates

“…The three gates have the disadvantage of high energy consumption. [3], (c) [4], (d) [5], (e) [6], (f) [7], (g) [8], and (h) [9].…”

“…In 2020, a new XOR/XNOR gate was proposed in [6], requiring two enable inputs. The design proposed by Laajimi et al has the advantage of small area but its energy dissipation is high [7]. Majeed et al [8] proposed a new XOR/XNOR gate and Safaiezadeh et al [9] implemented a three-input XOR/XNOR gate, both of them having the disadvantage of high energy dissipation.…”

Design of 2:4 and 3:8 decoder circuit using QCA technology

“…In the hold phase, the barrier remains high as the cells preserve their state. In the release phase, the cells become unpolarized as the potential barrier decreases and in relax phase they remain unpolarized [12,14].…”

“…This technology uses the Coulombic forces between charged particles. Unlike the CMOS technology, in QCA, they transfer the polarization of each cell [12]. Hence, polarization of QCA cell plays a very important role in choosing the perfect QCA device for use.…”

Realization of combinational logic circuits using standard functions in quantum dot cellular automata

“…The fundamental structural unit of Quantum Dot Cellular Automata is the QCA Cell. Each cell consists of four conductors in the form of metal islands [2,3] that forms the quantum dots. The paper is framed with the overview of the basic concept of Quantum dot cellular automata, and then it discussed 13 standard functions.…”