Combining embedding and synthesis for reversible logic, tcad, 2017. Quantumdot cellular automata qca as technology is a promising candidate that has tremendous potential to replace cmos due to its outstanding features such as lowpower, extremely high density, fast operation speed. The introduction of the ternary quantumdot cell enabled ternary computing, and with the recent development of a ternary functionally complete set of elementary logic primitives and the ternary memorizing cell design of complex processing structures is becoming feasible. Among these evolving nanotechnologies, quantumdot cellular automata is the most favorable technology 1. Recent advances in molecular implementations 2, which will enable room temperature operation, is particularly exciting. Pdf quantumdot cellular automata qca is a computational. Since the operational logic in qca is the majority logic. Quantumdot cellular automata is a novel paradigm for computing at the nanoscale. A novel design and implementation of 83 encoder using. The device under study was composed of four metal dots, connected with tunnel junctions and capacitors, and operated at material implementation free download as powerpoint presentation. Taylor baldwin, jeffrey will, douglas tougaw electrical and computer engineering valparaiso university valparaiso, indiana aaron. Quantumdot cellular automata serial decimal subtractors.
Quantumdot cellular automata adders western engineering. Conventional device physics is based on a free electron model which treats carriers in a material as if they were free electrons with a reduced effective mass which reflects the properties of the material. Computing with quantumdot cellular automata is enabled by quantummechanical tunneling and coulomb interactions. A binary qca is composed of binary quantum dot bqca cells, each of them containing four quantum dots and two electrons. Each qca device cell consists of a bistable or tristable semiconductor molecular structure of quantum dots.
The major advantages of this technology are lesser power dissipation, improved speed and dense structures. Cells are the basic computing element in quantumdot cellular automata and function as structured charge containers rather than as current switches. Since its early formulation in 1993 at notre dame university, the qca idea has received significant attention and several. Nanotechnology celebrates 25 years in an interview with the author of one of the most cited and downloaded papers.
We then introduce the concept of a quantum cellular automata and the various interesting properties it displays. Here, classical bits are encoded on the charge configuration of individual computing primitives known as cells. Qca devices can be realized in metal 2, or with chemical molecules 1. Research article design of efficient full adder in quantum. Quantum cellular automata university of notre dame. In quantum cellular automata we explore one such paradigm which has shown quite some potential over the past decade. The cellular automaton interpretation of quantum mechanics. Quantum dot cellular automata qca has been recognized as one of the technologies that may replace fieldeffect transistor fetbased computing devices at the nanoscale level. Quasiadiabatic switching for metalisland quantumdot. This fieldcoupled nanocomputing model is likely to challenge and succeed the cmos for roomtemperature operation when technological capability develops to the level of easily fabricating quantum dots of molecular size. An improved eigensolver for quantumdot cellular automata simulations a. Research in the fields of physics, chemistry and electronics has demonstrated that quantumdot cellular automata qca is a viable alternative for nanoscale computing. Lent, beth isaksen, and marya lieberman contribution from the center for nano science and technology, department of electrical engineering, and department of chemistry and biochemistry, university of notre dame, notre dame, indiana 46556 received may 10, 2002. Before discussing quantum dot cellular automata, it is worth discussing quantum dots and the confinement of electrons in the dots.
Quantum dot cellular automata is a novel paradigm for computing at the nanoscale. Device switching occurs through quantum mechanical inter dot. Quantum dot cellular automata qca as technology is a promising candidate that has tremendous potential to replace cmos due to its outstanding features such as lowpower, extremely high density, fast operation speed. A cell is a system of quantum dots with a few mobile charges. Qca is an abstract quantum computational nanotechnology based on fieldcoupled arrays of finitestate automata. Here is the first book devoted to quantum dot cellular automata qca an emerging nanoelectronic circuit design technology that more and more industry experts are viewing as a superior alternative to current technologies.
Signal energy in quantumdot cellular automata bit packets. Breaking landauers limit using quantumdot cellular automata. Pdf an overview is given of the qca architecture, along with a summary of experimental demonstrations of qca devices. During the keywords qca, memories, quantum dot cellular auromata, 1. A near zeroenergy computation using quantumdot cellular. For qca each cell is a finitedimensional quantum system and the update rule is unitary. Implementation of one bit parallel memory cell using.
Recently studied computational paradigms for quantumdot technology include the use of locally connected quantumdot cellular automata qca. A customizable quantumdot cellular automata building. Quantumdot cellular automata are an interesting nanoscale computing paradigm. The fundamental unit of quantum dot cellular automata is qca cell. Qca encodes binary information in the charge configuration within a cell. Quantum dot cellular automata in detailed explained youtube. Quantum dot cellular automata are an interesting nanoscale computing paradigm. Abstract quantum dot cellular automata qca is a novel and potentially attractive technology for implementing computing architectures at the nanoscale. Quantumdot cellular automata qca is a lowpower, nonvonneumann, generalpurpose paradigm for classical computing using transistorfree logic. Binary information is stored in the charge configuration. Quantumdot cellular automata qca has emerged as a new design paradigm for nanotechnologies. An mqca device combining a majority logic gate with binary wires.
Automatic design of optimal logic circuits based on ternary. Quantum dot cellular automata visit physics tomorrow webpage references. To advance the stateoftheart in qca computing by creating a standard library of qca circuits. The proposed subtractors are compared to the existing quantum. In this regard, quantumdot cellular automata qca 9. Memories, quantum dot cellular automata whose output is fed back into one of its inputs. A novel design for quantumdot cellular automata cells and. The 5bit johnsonmobius code is used to encode decimal digits. Synthesizing energy minimizing quantumdot cellular. Majority logic circuits optimisation by node merging ieee xplore.
Design and test of digital circuits by quantumdot cellular automata. The optimal geometry, shown in figure 2, has four coplanar carbons. Hall christof teuscher portland state university 2011. Quantumdot cellular automata qca is a promising architecture which employs quantum dots for digital computation. Computing with quantum dot cellular automata is enabled by quantum mechanical tunneling and coulomb interactions. Realization of a functional cell for quantumdot cellular. Quantumdot cellular automata represent binary information by charge configuration of cell. Twolayer synchronized ternary quantumdot cellular automata. Quantumdot cellular automata quantumdot cellular automata is a computing paradigm using arrays of nanostructures called quantum dots see what is a quantumdot. The first design leverages the complement addition method, while the second design uses the direct subtraction method. Implementation of one bit parallel memory cell using quatum.
Design of efficient full adder in quantum dot cellular automata bibhashsen, 1 ayushrajoria, 1 andbiplabk. An improved eigensolver for quantumdot cellular automata. In course of such a trend quantumdot cellular automata are getting projected as a promising nanotechnology for future ics lent, c. Automata qca allow for computations with very low energy dissipation and. It is a revolutionary approach which addresses the issues of device density and. Node duplication and routing algorithms for quantumdot cellular automata circuits w. Abstractquantumdot cellular automata qca is a digital. Logic realization using regular structures in quantumdot. Dec 29, 2012 two designs for quantum dot cellular automata serial decimal subtractors are proposed for a nanocomputer.
Introduction since the beginning of the cmos era the device sizes are continuously shrinking following the moore. Abstract the use of quantum dots is a promising emerging technology for implementing digital systems at the nanoscale level. Qca is transistorless computational paradigm which can achieve device density. Recently studied computational paradigms for quantum dot technology include the use of locally connected quantum dot cellular automata qca. Coulomb interaction between cells is sufficient to accomplish the computation in qca arrays, thus no interconnect. Abstract the use of quantumdots is a promising emerging technology for implementing digital systems at the nanoscale level. No matter where you are in your career, we would welcome you and encourage you to consider joining our community. Sep 17, 2016 the quantum dot based architecture is experimentally proven to work in the mkelvin temperature range. Quasiadiabatic switching for metalisland quantumdot cellular automata ge. Binary multipliers on quantumdot cellular automata 545 in out in out in out in out a in2 in3 in1 out b fig.
Quantumdot cellular automata qca 1 have potential for radically different form of computing. In this paper we present a novel design for qca cells and another possible and unconventional scheme for majority gates. Electrons, once trapped in the dot, do not alone posses the energy required to escape. We use hierarchical layout methods to combine fundamental quantumdot cellular automata. Although there are many open scientic and technical challenges at device level, strong case can be and has.
Published in 1993, it presented a specific model for. Quantumdot cellular automata qca has been recognized as one of the technologies that may replace fieldeffect transistor fetbased computing devices at the nanoscale level. Design of efficient full adder in quantumdot cellular automata bibhashsen, 1 ayushrajoria, 1 andbiplabk. This paper presents an experimental demonstration of a basic cell of the quantumdot cellular automata, a transistorless approach to computation that addresses the issues of device density, interconnection, and power dissipation. A binary qca is composed of binary quantumdot bqca cells, each of them containing four quantum dots and two electrons. Abstractquantum dot cellular automata qca is a novel and potentially attractive technology for implementing computing architectures at the nanoscale. The proposed basic building block can be customized to implement classical gates, such as xor and xnor gates, and reversible gates, such as cnot and toffoli gates. A customizable quantumdot cellular automata building block. The proposed subtractors are compared to the existing quantum dot cellular automata decimal adders. The quantum cellular automaton qca concept represents an attempt to break away from the traditional threeterminal device paradigm that has dominated digital computation. Exploring quantum dot cellular automata based reversible circuit.
Automatic cell placement for quantumdot cellular automata. A qca is a structure with predefined input, internal and output cells, capable of computing some logical function. Quantum dot cellular automata in detailed explained. Sikdar 2 department of computer science and engineering, national institute of technology, durgapur, india department of computer science and technology, bengal engineering and science university, shibpur, india. Quantumdot cellular automata qca 5 and resonant tunneling diodes rtd 6 are some of the beyond cmos technologies. Exploring quantum dot cellular automata based reversible. Quantum bits and quantum dot cellular automata beyond moores law with the expectation that present transistorbased technologies will reach their limits of scalability within 15 years, a number of alternative computational paradigms are being investigated. One of the most promising nanotechnologies which can replace the present transistor based cmos technology is the quantum dot cellular automata.
The cellular automaton interpretation of quantum mechanics gerard t hooft institute for theoretical physics utrecht university postbox 80. Quantumdot cellular automata qca is a novel computing mechanism that can represent binary information based on the spatial d istribution of electron charge con. Quantum cellular automata qca are a quantization of classical cellular automata ca, ddimensional arrays of cells with a finitedimensional state space and a local, spatiallyhomogeneous, discretetime update rule. Novel linear feedback shift register design in quantumdot. In qca, binary information is represented by bistable charge configuration. In this paper, a basic building block for qca will be proposed. Quantum dot cellular automata qca are nanoscale digital logic constructs that use electrons in arrays of quantum dots to carry out binary operations. The work in this paper describes the application of an optimized eigensolver algorithm to produce the kernel. Design and test of digital circuits by quantumdot cellular. Sequential circuit design using quantumdot cellular automata. The qca clock, its stages and its effects on a cells energy barriers.
The proposed basic building block can be customized to implement classical gates, such as xor and xnor gates, and reversible gates, such as cnot and toffoli gates, with less cell. Automatic design of optimal logic circuits based on. Qca is a novel emerging technology in which logic states are not stored as voltage levels, but rather the position of the individual electron 1. Design and test of digital circuits by quantumdot cellular automata fabrizo lombardi, jing huang on. Hierarchical design of quantumdot cellular automata devices. These include quantum dot cellular automata qca and quantum computing qc. Clock topologies for molecular quantumdot cellular automata. Cells are the basic computing element in quantum dot cellular automata and function as structured charge containers rather than as current switches. The quantum dotbased architecture is experimentally proven to work in the mkelvin temperature range. The same name may also refer to quantum dot cellular automata, which are a proposed physical implementation of classical cellular automata by exploiting quantum. In qca, binary information is encoded in the charge configuration within quantum dot cells. Quantum dot cellular automata qca is a lowpower, nonvonneumann, generalpurpose paradigm for classical computing using transistorfree logic. By combining the phase plots of the three dots, the var ious charge. Node duplication and routing algorithms for quantumdot.
One of the most promising nanotechnologies which can replace the present transistor based cmos technology is the quantumdot cellular automata. Logic realization using regular structures in quantumdot cellular automata qca by rahul singhal a thesis submitted in partial fulfillment of the requirement for the degree of master of science in electrical and computer engineering thesis committee. A wealth of experiments have been conducted with metal dot. Quantum dot cellular automata represent binary information by charge configuration of cell. The basic boolean primitive in qca is the majority gate. Research in the fields of physics, chemistry and electronics has demonstrated that quantum dot cellular automata qca is a viable alternative for nanoscale computing. Application of quantum technology in various fields is increasing day by day lent et al. May 22, 2014 nanotechnology celebrates 25 years in an interview with the author of one of the most cited and downloaded papers. Lenta department of electrical engineering, university of notre dame, notre dame, indiana 46556 received 2 september 1998. This technique is based on the interaction of electrons within quantum dots. Quantumdot cellular automata qca quantum dots are nanostructures nano. Design of an optimal decimal adder in quantum dot cellular. Quantumdot cellular automata qca are nanoscale digital logic constructs that use electrons in arrays of quantum dots to carry out binary operations.
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