Debarka Mukhopadhyay

A study on energy optimized 4 dot 2 electron two dimensional quantum dot cellular automata logical reversible flip-flops

In the present scope, new design methodologies for reversible flip flops are proposed and the results are analyzed by the QCADesigner tool. To the best of our knowledge such methodologies are reported for the first time in the literature. In this paper, we provide few formalisms also. The first one is for the system energy derived using Hamiltonian paradigm and provides internal energy of cell electrons. The second formalism provides the minimum energy requirement for execution of a QCA architecture. This procedure reduces wastage of clock energy. Two very interesting parameters are identified playing crucial role in this context: (i) The electron quantum number n which indicates quantum energy level and (ii) intermediate quantum number for an electron lying between 1 and (n-1). It is established that the incident energy frequency is directly proportional to the number of cells and quadratic function of electron quantum number and intermediate quantum number. The dissipated energy frequency is also directly proportional to the product of number of cells and quadratic function of electron quantum number. This paper, reports some remarkable results. The relaxation time is observed being inversely proportional to the product of number of cells in the architecture and quadratic function of quantum number as well as intermediate quantum number. Apart from these, differential frequency is found directly proportional to the number of cells in the architecture and quadratic function of intermediate quantum number. Few major observations are also indicated: (i) There is always a probability of reflection even if the system energy exceeds barrier energy. (ii) On the contrary, there is always a probability of transmission even though system energy is dominated by the barrier energy.

Designing and Implementation of Quantum Cellular Automata 2:1 Multiplexer Circuit

Quantum Cellular Automata is a promising nanotechnology that has been recognized as one of the top six emerging technology in future computers. We have developed a new methodology in design QCA 2:1 MUX having better area efficiency and less input to output delay. We have also shown that using this QCA 2:1 M UX as a unit higher M UX can also be designed. We verified the proposed design using simulation from QCADesigner tool. This simulator is also useful for building complex QCA circuits.

Quantum Cellular Automata based Novel Unit 2:1 Multiplexer

Quantum Cellular Automata (QCA) is an emerging nanotechnology and one of the top six technologies of the future. CMOS technology has a lot of limitations while scaling into a nano-level. QCA technology is a perfect replacement of CMOS technology with no such limitations. In this paper we have proposed one 2:1 multiplexer circuit having lowest complexity and area compared to the existing QCA based approaches. The proposed design is verified using QCADesigner.

A 2 Dot 1 Electron Quantum Cellular Automata Based Parallel Memory

In the present scope, a new design methodology of parallel memory is offered. It is designed using 2 dot 1 electron Quantum-Dot Cellular Automata (QCA) paradigm. This methodology ensures better efficiency and high degree of compactness. One bit design methodology can be extended to design multiple bit parallel memory. Here we present 2 bit memory using 2 dot 1 electron QCA.

New Architecture for Flip Flops Using Quantum-Dot Cellular Automata

This article proposes a thorough design and analysis of Quantum-dot Cellular Automata (QCA) flip flops. QCA is an emerging technology which provides implementation of digital technology at the nano-scale level. These circuits have the advantages of higher switching speed, smaller size and less power consumption compared to CMOS circuit. Compared to the previous designs this circuits have less number of cells and less area. All the proposed designs are simulated using the QCADesigner and the analysis of the result proves the validity of the circuits.

A novel parallel memory design using 2 Dot 1 electron QCA

In view of the technical limitations of CMOS technology, a serious research initiative is evident towards nanotechnology, as a substitution of the existing technology. Quantum-Dot Cellular Automata constitutes a major field of research in the nanotechnology domain. In this article we are dealing with 2 Dot 1 Electron QCA. This paper proposes a novel parallel memory design both single bit and multi-bit using 2 Dot 1 Electron QCA. The proposed design is going to preserve the stability measure and expected to be optimal.

Design and analysis of two Dot one Electron QCA Ex-OR gate in logically reversible gate design

Priorities of digital industry have changed over decades. Now-a-days nanotechnology grasp the major attention of digital industry. Quantum dot Cellular Automata(QCA) came out to be an efficient nanotechnology which can replace existing technologies in nanoscale. One of the well studied and researched variant of QCA is 4 Dot 2 Electron QCA. In the present scope our complete focus will be on 2 Dot 1 Electron QCA which is an emerging variant of QCA. This paper presents an improved design strategy of Ex-OR gate using 2 Dot 1 Elecron Quantum Cellular Automata(QCA) which consists of only 23 many 2 Dot 1 Electron QCA cells. The proposed design reduces the number of cells in comparison to the existing Ex-OR gate design in [1]. The proposed design of the EX-OR gate not only ensures high degree of compactness but also a huge reduction in the amount of required energy. This design strategy reduces the energy requirement as well as energy dissipation both upto 15 percent. The proposed Ex-OR gate implementation achieves upto 95.83 percent of compactness which is nothing but an index of area utilization. This design methodology of Ex-OR gate can be utilized to design multiple digital logic circuits. In our present perview we use the Ex-OR gate design to implement different reversible logic gates such as Tofolli gate and Feynman gate. We also suggest the design methodology of the Fredkin gate which is a reversible gate. To the best of our knowledge the designs of reversible gates using 2 Dot 1 Electron QCA have not been reported in literature yet. The proposed designs are analyzed with respect to different energy parameters.

Improved Quantum Dot Cellular Automata 4:1 Multiplexer Circuit Unit

Quantum dot cellular automata is one of the most efficient and emerging technology which mainly deals with the effect of electrons inside the quantum dots, and it is the best alternative technology in the nano level architectural field. In this paper we have designed a 4:1 MUX, which is more efficient and is also superior to the other recent designs. The proposed design includes reduction in cell count, area of the circuit, area of the cells and it improves the accuracy of the output. The results have been analyzed using QCA Designer.

2-Dimensional 2-Dot 1-Electron Quantum Cellular Automata-Based Dynamic Memory Design

Quantum dot cellular automata (QCA) is supposed to be the most promising technology which is an efficient nanotechnology and overcomes the limitations of the CMOS technology. Thus this technology is considered as the most preferable replacement of CMOS. This paper presents a design methodology of dynamic memory using 2-dot 1-electron QCA. According to the best of our knowledge, this has not been reported yet. The proposed design is supposed to be an optimum design with respect to cell requirement.

Design of a Logically Reversible Half Adder Using 2D 2-Dot 1-Electron QCA

Among the emerging technologies in the nanotechnology domain, quantum-dot cellular automata (QCA) is an important name. It overcomes the serious technical limitations of CMOS. In this article, we have used two-dimensional 2-dot 1-electron QCA cells, a variant of two-dimensional 4-dot 2-electron QCA cells, to design a logically reversible half adder. Potential energies have been computed to substantiate and analyse the proposed design. The issues related to energy and power dissipation have also been discussed. Finally, our proposed architecture using 2-dot 1-electron QCA cells has been compared with the architecture using 4-dot 2-electron QCA cells.