Energy can neither be created nor be destroyed but it can be conserved. The processors of present day computers are designed using conventional logic circuits which are irreversible in nature. They suffer from loss of information during computation, leading to energy dissipation in the form of heat affecting the performance and life of the circuits. These limitations of conventional logic circuits can be overcome by the reversible logic circuits designed using quantum gates, the essential elements for quantum computing. Quantum computing is an emerging area of research which finds application in optical computing, DNA computing, cryptography, low power CMOS design, digital signal processing and nanotechnology.
Energy can neither be created nor be destroyed but it can be conserved. The processors of present day computers are designed using conventional logic circuits which are irreversible in nature. They suffer from loss of information during computation, leading to energy dissipation in the form of heat affecting the performance and life of the circuits. These limitations of conventional logic circuits can be overcome by the reversible logic circuits designed using quantum gates, the essential elements for quantum computing. Quantum computing is an emerging area of research which finds application in optical computing, DNA computing, cryptography, low power CMOS design, digital signal processing and nanotechnology.
Abstract — Reversible logic is one of the most vital issue at present time and it has different areas for its application, those are low power CMOS, quantum computing, nanotechnology, cryptography, optical computing, DNA computing, digital signal processing (DSP), quantum dot cellular automata, communication, computer graphics. It is not possible to realize quantum computing without implementation of reversible logic. The main purposes of designing reversible logic are to decrease quantum cost, depth of the circuits and the number of garbage outputs. This paper provides the basic reversible logic gates, which in designing of more complex system having reversible circuits as a primitive component and which can execute more complicated operations using quantum computers. The reversible circuits form the basic building block of quantum computers as all quantum operations are reversible. This paper presents the data relating to the primitive reversible gates which are available in literature and helps researches in designing higher complex computing circuits using reversible gates.
Reversible logic is emerging as a promising computing paradigm with applications in ultralow power nanocomputing and emerging nanotechnologies such as quantum computing, quantum dot cellular automata (QCA), optical computing, etc. Reversible circuits are similar to conventional logic circuits except that they are built from reversible gates. In reversible gates, there is a unique, one-to-one mapping between the inputs and outputs, not the case with conventional logic. One of the primary motivations for adopting reversible logic lies in the fact that it can provide a logic design methodology for designing ultra-low power circuits beyond KTln2 limit for those emerging nanotechnologies in which the energy dissipated due to information destruction will be a significant factor of the overall heat dissipation. Further, logic circuits for quantum computers must be built from reversible logic components. Several important metrics need to be considered in the design of reversible circuits the importance of which needs to be discussed. Quantum computers of many qubits are extremely difficult to realize thus the number of qubits in the quantum circuits needs to be minimized. This sets the major objective of optimizing the number of ancilla inputs and the number of the garbage outputs in the reversible logic based quantum circuits. The constant input in the reversible quantum circuit is called the ancilla input, while the garbage output refers to the output which exists in the circuit just to maintain one-to-one mapping but is not a primary or a useful output. The reversible circuit has other important parameters of quantum cost and delay which need to be optimized.
Abstract: Reversible logic is one of the most important issues at the moment and has a wide range of applications, such as low power CMOS, quantum computing, nanotechnol- ogy, cryptography, optical computing, DNA computing, and -digital signal processing (DSP), quantum Dot automata for mobile, communication, computer graphics. It is not possible to detect quantum computing without the implementation of a postponed brain operation. The main objectives of design are logical thinking to reduce quantum costs, circuit depths and the amount of waste disposal. This paper provides basic logical retrospective gates, which in the construction of a highly sophisticated system with retractable circuits as part of the old and unable to perform the most complex operations using quantum computers. Reversible circuits form the basic building block of quantum computers as all quantum functions are reversed. This paper presents data related to older retractable gates found in books and assists research in the design of complex computer circuits using retractable gates. Keywords: Defendable Logic, Portable Gate, Dismissal, Trash, Quantum Cost, Quantum-dot Cellular Automata, Reversible Computing, Reversible ALU, Flip Flop using Reversible Gates, Reversible Adder
Quantum Dot Cellular Automata (QCA) is a rising innovation which seems to be a good competitor for the next generation of digital systems and widely utilized as a part of advanced frameworks.It is an appealing substitute to ordinary CMOS innovation because of diminutive size, faster speed, extremely scalable feature, ultralow power consumption and better switching frequency.The realization of quantum computation is not possible without reversible logic.Reversible logic has enlarged operations in quantum computation.Generally reversible computing is executed when system composes of reversible gates.It has numerous fields of use as applied science, quantum dot cellular automata as well as low power VLSI circuits, low power CMOS, digital signal processing, computer graphics.In this paper, the quantum implementation of primitive reversible gate has been presented.The proposed gates have been designed and simulated using QCADesigner.
This work presents the logical reversibility. The inputs and outputs of reversible logic gates can be uniquely retrievable from each other. The reversible logic operations can't erase information and dissipate zero heat. The circuit actually operates in a backward operation, allows reproducing the inputs from the outputs and consumes zero power. As the basic elements of any logic circuit, logic gates are used to realize Boolean functions. By combining reversible logic gates, reversible circuits can perform complex logical and arithmetic operations. A one-to-one mapping between inputs and outputs is realized. The logical operations run backwards by cascading a reversible logic gate with its dual (inverse). Reversible circuits are also called lossless circuits, as there is neither energy loss nor information loss. These circuits are very attractive for applications where extremely low power consumption, or heat dissipation, is desirable in areas ranging from communications, low power VLSI (very large-scale integration) technology, optical computing to nanotechnology. Reversible logic found to be very useful in quantum computing where the quantum evolution is inherently reversible.
At present days , reversible logic circuits have many applications in the field of optical information processing, digital signal processing , nano technology and quantum computing . Reversible logic plays an important role when computations with minimum energy dissipation are considered. The purpose of designing reversible logic is to decrease the number of area, power, garbage outputs , constant inputs, quantum cost, reversible gates, delay and hardware complexity . This paper reveals a review on some reversible logic gates, which is useful in designing more complex systems having reversible circuits and can do execution of more complex operations using quantum computers. In upcoming days digital technology will be using reversible logic gates in order to reduce the propagation delay and power consumption as it provides negligible loss of information in the circuit. Keywords: Reversible Gate, Garbage output, quantum cost, Reversible logic, Power dissipation