An Insight into Beyond CMOS Next Generation Computing using Quantum-dot Cellular Automata Nanotechnology

Abstract

CMOS is a technology that has revolutionized the field of electronics. Over the time the processing technologies and design methodologies of CMOS devices have proved to be in full swing with the Moore's law and the miniaturization paradigm. However, after surviving for more than five decades, CMOS is now facing challenges to live through the submicron ranges. The scaling in CMOS has reached a higher limit, showing adverse effects not only from physical and technological point of view but also from material and economical perspective. This drift inspires the researchers to look for new promising alternatives to CMOS which vow better performance, density and power consumption. One of the promising alternatives to digital designing in CMOS is the Quantum-dot Cellular Automata (QCA). QCA is a technology that involves no current transfer but works on electronic interaction between the cells. The QCA cell basically consists of quantum dots separated by certain distance and the entire transmission of information occurs via the interaction between the electrons localized in these quantum dots. In this paper the limitations to CMOS in submicron range and concepts for designing in QCA have been discussed. Further the building blocks are explained theoretically as well as using QCA Designer implementations with focus on cell interaction and clocking mechanisms.

Quantum dot Cellular Automata based Fault Tolerant Fingerprint Authentication Systems using Reversible Logic Gates

“…As seen in Figure 1, one of the electron locations describes '1' while the other describes '0.' Figure 2 shows the cells forming a QCA wire in tandem [3,33]. • QCA Logic Gates: As shown in Figure 3(a), the basic logic gate in QCA is a three-input majority voter gate [3,9].…”

“…In the hold phase, the cell maintains its initial state and maintains a high level of potential vitality. The potential liveliness of the electrons begins to decrease during the release and relax phase, eventually returning to null polarization [3,12,33].…”

Design of quantum‐dot cellular automata‐based communication system using modular N‐bit binary to gray and gray to binary converters

“…For proper routing of information, QCA has four clock zones: zones 0 through 3, shown in Figure 1B, having each having a phase difference of 90 with respect to previous clock zone. 31,32 The majority voter gate along with inverter form the basic devices in QCA, shown in Figure 1C-E, respectively. The Boolean expression according to which the majority gate functions is M(A, B, C) = AB + BC + CA.…”

“…The polarity of a cell is decided by its neighboring cells. For proper routing of information, QCA has four clock zones: zones 0 through 3, shown in Figure 1B, having each having a phase difference of 90° with respect to previous clock zone 31,32 . The majority voter gate along with inverter form the basic devices in QCA, shown in Figure 1C–E, respectively.…”

Multioperative reversible gate design with implementation of 1‐bit full adder and subtractor along with energy dissipation analysis

“…A wire in QCA is implemented by placing QCA cells in tandem, one after another. Data are transmitted through the wire by a phenomenon of pipelining 5 . In a QCA wire, the cells can be at different clock phases.…”