Emerging Design Methodology And Its Implementation Through Rns And Qca

Digital logic technology has been changing dramatically from integrated circuits, to a Very Large Scale Integrated circuits (VLSI) and to a nanotechnology logic circuits. Research focused on increasing the speed and reducing the size of the circuit design. Residue Number System (RNS) architecture has ability to support high speed concurrent arithmetic applications. To reduce the size, Quantum-Dot Cellular Automata (QCA) has become one of the new nanotechnology research field and has received a lot of attention within the engineering community due to its small size and ultralow power. In the last decade, residue number system has received increased attention due to its ability to support high speed concurrent arithmetic applications such as Fast Fourier Transform (FFT), image processing and digital filters utilizing the efficiencies of RNS arithmetic in addition and multiplication. In spite of its effectiveness, RNS has remained more an academic challenge and has very little impact in practical applications due to the complexity involved in the conversion process, magnitude comparison, overflow detection, sign detection, parity detection, scaling and division. The advancements in very large scale integration technology and demand for parallelism computation have enabled researchers to consider RNS as an alternative approach to high speed concurrent arithmetic. Novel parallel - prefix structure binary to residue number system conversion method and RNS novel scaling method are presented in this thesis. Quantum-dot cellular automata has become one of the new nanotechnology research field and has received a lot of attention within engineering community due to its extremely small feature size and ultralow power consumption compared to COMS technology. Novel methodology for generating QCA Boolean circuits from multi-output Boolean circuits is presented. Our methodology takes as its input a Boolean circuit, generates simplified XOR-AND equivalent circuit and output an equivalent majority gate circuits. During the past decade, quantum-dot cellular automata showed the ability to implement both combinational and sequential logic devices. Unlike conventional Boolean AND-OR-NOT based circuits, the fundamental logical device in QCA Boolean networks is majority gate. With combining these QCA gates with NOT gates any combinational or sequential logical device can be constructed from QCA cells. We present an implementation of generalized pipeline cellular array using quantum-dot cellular automata cells. The proposed QCA pipeline array can perform all basic operations such as multiplication, division, squaring and square rooting. The different mode of operations are controlled by a single control line

New Data Structures and Algorithms for Logic Synthesis and Verification

The strong interaction between Electronic Design Automation (EDA) tools and Complementary Metal-Oxide Semiconductor (CMOS) technology contributed substantially to the advancement of modern digital electronics. The continuous downscaling of CMOS Field Effect Transistor (FET) dimensions enabled the semiconductor industry to fabricate digital systems with higher circuit density at reduced costs. To keep pace with technology, EDA tools are challenged to handle both digital designs with growing functionality and device models of increasing complexity. Nevertheless, whereas the downscaling of CMOS technology is requiring more complex physical design models, the logic abstraction of a transistor as a switch has not changed even with the introduction of 3D FinFET technology. As a consequence, modern EDA tools are fine tuned for CMOS technology and the underlying design methodologies are based on CMOS logic primitives, i.e., negative unate logic functions. While it is clear that CMOS logic primitives will be the ultimate building blocks for digital systems in the next ten years, no evidence is provided that CMOS logic primitives are also the optimal basis for EDA software. In EDA, the efficiency of methods and tools is measured by different metrics such as (i) the result quality, for example the performance of a digital circuit, (ii) the runtime and (iii) the memory footprint on the host computer. With the aim to optimize these metrics, the accordance to a specific logic model is no longer important. Indeed, the key to the success of an EDA technique is the expressive power of the logic primitives handling and solving the problem, which determines the capability to reach better metrics. In this thesis, we investigate new logic primitives for electronic design automation tools. We improve the efficiency of logic representation, manipulation and optimization tasks by taking advantage of majority and biconditional logic primitives. We develop synthesis tools exploiting the majority and biconditional expressiveness. Our tools show strong results as compared to state-of-the-art academic and commercial synthesis tools. Indeed, we produce the best results for several public benchmarks. On top of the enhanced synthesis power, our methods are the natural and native logic abstraction for circuit design in emerging nanotechnologies, where majority and biconditional logic are the primitive gates for physical implementation. We accelerate formal methods by (i) studying properties of logic circuits and (ii) developing new frameworks for logic reasoning engines. We prove non-trivial dualities for the property checking problem in logic circuits. Our findings enable sensible speed-ups in solving circuit satisfiability. We develop an alternative Boolean satisfiability framework based on majority functions. We prove that the general problem is still intractable but we show practical restrictions that can be solved efficiently. Finally, we focus on reversible logic where we propose a new equivalence checking approach. We exploit the invertibility of computation and the functionality of reversible gates in the formulation of the problem. This enables one order of magnitude speed up, as compared to the state-of-the-art solution. We argue that new approaches to solve EDA problems are necessary, as we have reached a point of technology where keeping pace with design goals is tougher than ever

Opportunities for radio frequency nanoelectronic integrated circuits using carbon-based technologies

This thesis presents a body of work on the modeling of and performance predictions for carbon nanotube field-effect transistors (CNFET) and graphene field-effect transistors (GFET). While conventional silicon-based CMOS is expected to reach its ultimate scaling limits during the next decade, these two novel technologies are promising candidates for future high-performance electronics. The main goal of this work is to investigate on the opportunities of using such carbon-based electronics for RF integrated circuits. This thesis addresses 1) the modeling of noise and process variability in CNFETs, 2) RF performance predictions for CNFETs, and 3) an accurate GFET compact model. This work proposes the first CNFET noise compact model. Noise is of primary importance for RF applications and its description significantly increases the insight gained from simulation studies. Furthermore, a CNFET variability model is presented, which handles tube synthesis and metal tube removal imperfections. These two model extensions have been added to the Stanford CNFET compact model and allow for the variability-aware RF performance assessment of the CNFET technology. In continuation, comprehensive RF performance projections for CNFETs are provided both on the device and circuit level. The overall set of ITRS RF-CMOS technology requirement FoMs is determined and shows that the CNFET performs excellently in terms of speed, gain, and minimum noise figure. Furthermore, for the first time FoMs are reported for the basic RF building blocks low-noise amplifier and oscillator. In addition, it is shown that CNFET downscaling yields significant performance improvements. Based on these analyses it is confirmed that the CNFET has the potential to outperform Si-CMOS in RF applications. A third key contribution of this thesis is the development of an accurate GFET compact model. Previous compact models simplify several physical aspects, which can cause erroneous simulation results. Here, an accurate yet simple mathematical description of the GFET’s current-voltage relation is proposed and implemented in Verilog-A. Comprehensive error analyses are done in order to highlight the advantages of the new approach. Furthermore, the model is verified against measurement results. The developed GFET model is an important step towards better understanding the characteristics and opportunities of graphene-based analog circuitry

Quantitative Automated Object Wave Restoration in High-Resolution Electron Microscopy

The main problem addressed by this dissertation is the accurate and automated determination of electron microscope imaging conditions. This enables the restoration of the object wave, which confers direct structural information about the specimen, from sets of differently aberrated images. An important member in the imaging chain is the image recording device, in many cases now a charge-coupled device (CCD) camera. Previous characterisations of these cameras often relied on the unjustified assumption that the Modulation Transfer Function (MTF) also correctly describes the spatial frequency dependent attenuation of the electron shot noise. A new theory is therefore presented that distinguishes between signal and noise transfer. This facilitates the evaluation of both properties using a detailed Monte-Carlo simulation model for the electron and photon scattering in the scintillator of the camera. Furthermore, methods for the accurate experimental determination of the signal and noise transfer functions are presented. In agreement with the Monte-Carlo simulations, experimental results for commercially available CCD cameras show that the signal transfer is significantly poorer than the noise transfer. The centrepiece of this dissertation is the development of new methods for determining the relative aberrations in a set of images and the absolute symmetric aberrations in the restored wave. Both are based on the analysis of the phase information in the Fourier domain and give each Fourier component a weight independent of its strength. This makes the method suitable even for largely crystalline samples with little amorphous contamination, where conventional methods, such as automated diffractogram fitting, usually fail. The method is then extended to also cover the antisymmetric aberrations, using combined beam tilt and focal series. The applicability of the new method is demonstrated with object wave restorations from tilt and focal series of complex inorganic block oxides and of carbon nanotubes filled with one-dimensional inorganic crystals. The latter specimens allowed for the first time a direct comparison between the phase shift in the restored object wave of a specimen with precisely known thickness and the value predicted by simulations

Ignition and burn in perturbed inertial confinement fusion hotspots

This work explores how perturbations affect the performance of inertial confinement fusion hotspots through the inhibition of ignition and the effect on burn propagation post-ignition. To model this, a 3D Monte-Carlo charged particle transport module has been developed for the radiation-magnetohydrodynamics code Chimera. The behaviour of the hotspot and the hotspot power balance in three alpha-heating regimes - self-heating, robust ignition and propagating burn - are explored in 1D through hydrodynamic scaling with capsule size and laser energy, demonstrating strong alpha-heating effects on the hydrodynamic evolution. The hotspot’s definition affects calculated hotspot parameters, particularly in weak alpha-heating regimes where the boundary between the hotspot and the shell is less well-defined. The impact of perturbations on the hotspot was explored using idealised spike and bubble perturbations. Less efficient PdV heating of the hotspot reduces the strength of the alpha-heating bootstrap. The spike significantly increased heat flow out of the hotspot from thermal conduction and alpha-heating; due to larger temperature gradients and surface area around the spike, and the closer proximity of cold, dense material to the primary fusion regions respectively. The bubble’s effect on the hotspot power losses was minimal, but re-expansion into the bubble reduced confinement and truncated burn. 3D implosions based on National Ignition Facility Highfoot and High-Density Carbon (HDC) designs were perturbed using short-wavelength multi-mode and long-wavelength radiation asymmetry perturbations and scaled with capsule size and laser energy. The multi-mode yield increased faster with scale factor due to more synchronous P dV compression producing higher temperatures, and therefore stronger alpha-heating bootstrapping. Significant yield degradation for the Highfoot design resulted in only modest improvements in yield from scaling, whereas the less degraded HDC design demonstrated non-linear yield scaling. Perturbed implosions in the propagating burn regime exhibited fire-polishing due to thermal conduction and alpha-heating, in addition to "aneurysm"-like loss of confinement.Open Acces

Graphene under strain. A combined continuum-atomistic approach

By combining continuum elasticity theory and atomistic simulations, we provide a picture of the elastic behavior of graphene, which was addressed as a two-dimensional crystal membrane. Thus, the constitutive nonlinear stress-strain relations for graphene, as well as its hydrogenated conformers, have been derived in the framework of the two-dimensional elastic theory, and all the corresponding linear and nonlinear elastic moduli have been computed by atomistic simulations. Moreover, we discuss the effects of an applied stretching on graphene lattice to its electronic band structure, in particular regards the concept of strain-induced band gap engineering. Finally, we focus on the emergence of a stretching field induced on a graphene nanoribbon by bending, providing that such an in-plane strain field can be decomposed in a first contribution due to the actual bending of the sheet and a second one due to the edge effects induced by the finite size of the nanoribbon.------------------------------------------------------ABSTRACT ITA-------Combinando la teoria dell‘elasticità del continuo con calcoli eseguiti attraverso simulazioni atomistiche, si è affrontato lo studio del comportamento elastico del grafene, ovvero di una struttura cristallina bidimensionale a base carbonio. In tal modo, nell‘ambito della teoria elastica bidimensionale, sono state derivate le equazioni costitutive non lineari per il grafene e per il suo composto con l‘idrogeno, detto grafane; conseguentemente sono stati determinati per mezzo di simulazioni atomistiche tutti i relativi moduli elastici lineari e non lineari. Inoltre, abbiamo discusso gli effetti dovuti a deformazioni omogenee applicate al reticolo di grafene sulle sue bande elettroniche, con particolare attenzione al concetto di ingegnerizzazione della gap elettronica indotta da deformazione. Infine, discutiamo l‘insorgenza di un campo di deformazione su un campione di grafene finito sottoposto a piegamento, evidenziando come tale campo possa essere decomposto in un contributo causato della flessione reale subita e in un secondo dovuto ai soli effetti di bordo.

Graphene under strain. A combined continuum-atomistic approach

By combining continuum elasticity theory and atomistic simulations, we provide a picture of the elastic behavior of graphene, which was addressed as a two-dimensional crystal membrane. Thus, the constitutive nonlinear stress-strain relations for graphene, as well as its hydrogenated conformers, have been derived in the framework of the two-dimensional elastic theory, and all the corresponding linear and nonlinear elastic moduli have been computed by atomistic simulations. Moreover, we discuss the effects of an applied stretching on graphene lattice to its electronic band structure, in particular regards the concept of strain-induced band gap engineering. Finally, we focus on the emergence of a stretching field induced on a graphene nanoribbon by bending, providing that such an in-plane strain field can be decomposed in a first contribution due to the actual bending of the sheet and a second one due to the edge effects induced by the finite size of the nanoribbon.------------------------------------------------------ABSTRACT ITA-------Combinando la teoria dell‘elasticità del continuo con calcoli eseguiti attraverso simulazioni atomistiche, si è affrontato lo studio del comportamento elastico del grafene, ovvero di una struttura cristallina bidimensionale a base carbonio. In tal modo, nell‘ambito della teoria elastica bidimensionale, sono state derivate le equazioni costitutive non lineari per il grafene e per il suo composto con l‘idrogeno, detto grafane; conseguentemente sono stati determinati per mezzo di simulazioni atomistiche tutti i relativi moduli elastici lineari e non lineari. Inoltre, abbiamo discusso gli effetti dovuti a deformazioni omogenee applicate al reticolo di grafene sulle sue bande elettroniche, con particolare attenzione al concetto di ingegnerizzazione della gap elettronica indotta da deformazione. Infine, discutiamo l‘insorgenza di un campo di deformazione su un campione di grafene finito sottoposto a piegamento, evidenziando come tale campo possa essere decomposto in un contributo causato della flessione reale subita e in un secondo dovuto ai soli effetti di bordo.

Quantum Nonlocality

This book presents the current views of leading physicists on the bizarre property of quantum theory: nonlocality. Einstein viewed this theory as “spooky action at a distance” which, together with randomness, resulted in him being unable to accept quantum theory. The contributions in the book describe, in detail, the bizarre aspects of nonlocality, such as Einstein–Podolsky–Rosen steering and quantum teleportation—a phenomenon which cannot be explained in the framework of classical physics, due its foundations in quantum entanglement. The contributions describe the role of nonlocality in the rapidly developing field of quantum information. Nonlocal quantum effects in various systems, from solid-state quantum devices to organic molecules in proteins, are discussed. The most surprising papers in this book challenge the concept of the nonlocality of Nature, and look for possible modifications, extensions, and new formulations—from retrocausality to novel types of multiple-world theories. These attempts have not yet been fully successful, but they provide hope for modifying quantum theory according to Einstein’s vision

A High Speed Low Power Modulo 2ⁿ + 1 Multiplier Design using Carbon-Nanotube Technology

Modulo 2n + 1 multiplier is one of the critical components in the area of digital signal processing, residue arithmetic, and data encryption that demand high-speed and low-power operation. In this paper, a new circuit implementation of a high-speed low-power modulo 2n + 1 multiplier is proposed. It has three major stages: partial product generation stage, partial product reduction stage, and the final adder stage. The proposed structure introduces a new MUX-based compressor in the partial product reduction stage to reduce power and increase speed, and in the final adder stage, the Sparse-tree-based inverted end-around-carry adder reduces the number of critical path circuit blocks, also avoids wire interconnection problem. The proposed multiplier is implemented using both 32nm CNTFET (Carbon-Nanotube FET) and bulk CMOS technology for performance comparison. The CNTFET-based design dramatically decreases the PDP (Power Delay Product) of the circuit. The simulation results demonstrate that the power consumption of CNTFET-based multiplier is at average 5.72 times less than its CMOS counterpart, while the PDP of CNTFET is 94 times less than the CMOS one