Intelligent Circuits and Systems

ICICS-2020 is the third conference initiated by the School of Electronics and Electrical Engineering at Lovely Professional University that explored recent innovations of researchers working for the development of smart and green technologies in the fields of Energy, Electronics, Communications, Computers, and Control. ICICS provides innovators to identify new opportunities for the social and economic benefits of society.　 This conference bridges the gap between academics and R&D institutions, social visionaries, and experts from all strata of society to present their ongoing research activities and foster research relations between them. It provides opportunities for the exchange of new ideas, applications, and experiences in the field of smart technologies and finding global partners for future collaboration. The ICICS-2020 was conducted in two broad categories, Intelligent Circuits & Intelligent Systems and Emerging Technologies in Electrical Engineering

Recent Trends in Communication Networks

In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges

Towards Computational Efficiency of Next Generation Multimedia Systems

To address throughput demands of complex applications (like Multimedia), a next-generation system designer needs to co-design and co-optimize the hardware and software layers. Hardware/software knobs must be tuned in synergy to increase the throughput efficiency. This thesis provides such algorithmic and architectural solutions, while considering the new technology challenges (power-cap and memory aging). The goal is to maximize the throughput efficiency, under timing- and hardware-constraints

Reinventing Integrated Photonic Devices and Circuits for High Performance Communication and Computing Applications

The long-standing technological pillars for computing systems evolution, namely Moore\u27s law and Von Neumann architecture, are breaking down under the pressure of meeting the capacity and energy efficiency demands of computing and communication architectures that are designed to process modern data-centric applications related to Artificial Intelligence (AI), Big Data, and Internet-of-Things (IoT). In response, both industry and academia have turned to \u27more-than-Moore\u27 technologies for realizing hardware architectures for communication and computing. Fortunately, Silicon Photonics (SiPh) has emerged as one highly promising ‘more-than-Moore’ technology. Recent progress has enabled SiPh-based interconnects to outperform traditional electrical interconnects, offering advantages like high bandwidth density, near-light speed data transfer, distance-independent bitrate, and low energy consumption. Furthermore, SiPh-based electro-optic (E-O) computing circuits have exhibited up to two orders of magnitude improvements in performance and energy efficiency compared to their electronic counterparts. Thus, SiPh stands out as a compelling solution for creating high-performance and energy-efficient hardware for communication and computing applications. Despite their advantages, SiPh-based interconnects face various design challenges that hamper their reliability, scalability, performance, and energy efficiency. These include limited optical power budget (OPB), high static power dissipation, crosstalk noise, fabrication and on-chip temperature variations, and limited spectral bandwidth for multiplexing. Similarly, SiPh-based E-O computing circuits also face several challenges. Firstly, the E-O circuits for simple logic functions lack the all-electrical input handling, raising hardware area and complexity. Secondly, the E-O arithmetic circuits occupy vast areas (at least 100x) while hardly achieving more than 60% hardware utilization, versus CMOS implementations, leading to high idle times, and non-amortizable area and static power overheads. Thirdly, the high area overhead of E-O circuits hinders them from achieving high spatial parallelism on-chip. This is because the high area overhead limits the count of E-O circuits that can be implemented on a reticle-size limited chip. My research offers significant contributions to address the aforementioned challenges. For SiPh-based interconnects, my contributions focus on enhancing OPB by mitigating crosstalk noise, addressing the optical non-linearity-related issues through the development of Silicon-on-Sapphire-based photonic interconnects, exploring multi-level signaling, and evaluating various device-level design pathways. This enables the design of high throughput (\u3e1Tbps) and energy-efficient (\u3c1pJ/bit) SiPh interconnects. In the context of SiPh-based E-O circuits, my contributions include the design of a microring-based polymorphic E-O logic gate, a hybrid time-amplitude analog optical modulator, and an indium tin oxide-based silicon nitride microring modulator and a weight bank for neural network computations. These designs significantly reduce the area overhead of current E-O computing circuits while enhancing the energy-efficiency, and hardware utilization

NASA Tech Briefs, February 1997

Topics include: Test and Measurement; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery/Automation; Manufacturing/Fabrication; Mathematics and Information Sciences; Life Sciences; Books and Report

Remote Sensing

This dual conception of remote sensing brought us to the idea of preparing two different books; in addition to the first book which displays recent advances in remote sensing applications, this book is devoted to new techniques for data processing, sensors and platforms. We do not intend this book to cover all aspects of remote sensing techniques and platforms, since it would be an impossible task for a single volume. Instead, we have collected a number of high-quality, original and representative contributions in those areas

Defect Engineering in HfO2/TiN-based Resistive Random Access Memory (RRAM) Devices by Reactive Molecular Beam Epitaxy

Recently, there has been huge interest in emerging memory technologies, spurred by the ever increasing demand for storage capacities in various applications like Internet of Things (IoT), Big Data, etc. CMOS based flash memory, the current mainstay of the memory technology, has been able to increase its density by scaling down to a 16 nm node and further implementation of 3D architectures. However, flash memory is expected to soon run into disadvantage due to challenges in further scaling. Therefore, extensive efforts are being made towards developing new devices for the next generation of non-volatile memories with the combined advantages of flash memory like non-volatility, high density, low cost and low power consumption as well as high speed performance of DRAM. Among the many competitors, resistive random access memories (RRAM) based on resistive switching in oxides are promising due to its simple metal-insulator-metal (MIM) structure, fast switching speeds (<10 ns), excellent scalability (<10 nm) and potential for multi-level switching. RRAM devices based on the popular dielectric-metal gate combination of hafnium oxide (HfO2) and titanium nitride (TiN), which is the subject of research in this work, are particularly interesting due to its compatibility with existing CMOS technology in addition to the aforementioned advantages. Though prototype RRAM chips have already been demonstrated, key problems for commercial realization of RRAM include large variability and insufficient understanding of the complex switching physics. Resistive switching mechanism in oxides is generally understood to be mediated via the transport of oxygen ions leading to the formation of a conductive filament composed of oxygen vacancy defects. Appropriate defect engineering approaches offer potential towards tailoring the switching behavior as well as improving the performance and yield of HfO2-RRAM. In this thesis, the impact of pre-induced defects on the resistive switching behavior of HfO2-RRAM is investigated in detail and our results are presented. Defect engineered oxide thin films were deposited using reactive molecular beam epitaxy (RMBE) to fabricate metal oxide/TiN based devices. RMBE technique offers the unique possibility to precisely and reproducibly control the oxygen stoichiometry of the thin films in a wide range. Using RMBE, defects were introduced in polycrystalline HfOx thin films intrinsically by oxygen stoichiometry engineering and extrinsically via impurity doping (trivalent lanthanum and pentavalent tantalum). Both the studies were performed at at CMOS compatible deposition temperatures (< 450 °C) with an eye on practical applications. Prior to tantalum doping in HfO2, oxygen stoichiometry engineering studies were also performed in amorphous tantalum oxide (TaOx) thin films to identify the oxidation conditions of tantalum metal. The density of oxygen stoichiometry engineered thin films of HfOx and TaOx could be tuned in a wide range from that of the bulk oxide density to close to metallic density. High degree of oxygen deficiency in oxides led to the formation of defect states near the Fermi level as well as multiple oxidation states of the metal, as observed by X-ray photoelectron spectroscopy (XPS). The pure stoichiometric hafnium oxide films crystallize as expected in a stable monoclinic structure (m-HfO2) whereas, oxygen deficient HfOx thin films were found to crystallize in vacancy stabilized tetragonal like structure (t-HfO2-x). Impurity doping also led to the stabilization of higher symmetry tetragonal (t-Ta:HfOx) or cubic structures (c-La:HfOx) depending on the ionic radii of the dopant. The growth of TiN thin films was also investigated using RMBE. The devices used for electrical studies in this work mostly involved deposition of oxides by RMBE on polycrystalline TiN/Si electrodes after ex-situ transfer for further deposition. Therefore, RMBE grown TiN thin film electrodes with similar or better quality would allow in-situ uninterrupted deposition of subsequent oxide layers in future to form cleaner interfaces. Optimized conditions for growth of epitaxial TiN films on the commercially relevant (001) oriented silicon and c-cut sapphire substrates were established, with focus on achieving smooth surfaces and low resistivity. High quality epitaxial TiN(111)||Al2O3(0001) and TiN(001)||Si(001) films with a low resistivity (20-200 uOhm.cm) were achieved, in spite of the large lattice mismatch. Very low surface roughness, characterized by a streaky reflection high energy electron diffraction (RHEED) pattern during TiN film growth was additionally obtained, by tuning the Ti/N flux ratios. Oxygen engineered HfOx/TiN devices were further electrically characterized to obtain I-V characteristics during quasi-static DC switching. Usually, an initial electroforming step (high voltages) is required to obtain further reproducible switching operation (at lower voltages). High device to device variability in RRAM is typically associated with the stochastic nature of electroforming process which increases at higher forming voltages. Using highly oxygen deficient HfOx and TaOx films, the forming voltages were found to be reduced to levels close to operating voltages, paving the way for forming-free devices. However, the use of high defect concentration adds to increasing the complexity of the switching mechanism. This is reflected in the rather complex and dissimilar switching behaviors observed in the myriad of similar RRAM devices reported in the rapidly growing literature. Using model Pt/HfOx/TiN-based device stacks; it is shown that a well-controlled oxygen stoichiometry governs the filament formation and the (partial) occurrence of multiple resistive switching modes (bipolar, unipolar, threshold, complementary). These findings fuel a better fundamental understanding of the underlying phenomena for future theoretical considerations. The oxygen vacancy concentration is found to be the key factor in manipulating the balance between electric field and Joule heating during formation, rupture (reset), and reformation (set) of the conductive filaments in the dielectric. While a bipolar switching occurs in all the devices irrespective of defect concentration, switching modes like unipolar and threshold switching is favored only at higher oxygen stoichiometry. This suggests the suppression of thermal effects via higher heat dissipation and lowered concentration gradient of oxygen vacancies in oxygen deficient devices. A qualitative switching model based on the drift, diffusion and thermophoresis of oxygen ions is suggested to account for the partial occurrence of various switching modes depending on the oxygen stoichiometry. Further, the evolution or drift of high resistance states during endurance test of the common bipolar operation is compared for HfO2 and HfO1.5 based devices and interpreted using the quantum point contact (QPC) model. Similar observations regarding switching modes were also obtained in oxygen engineered Pt/TaOx/TiN devices, therefore allowing the findings to be generalized to other filamentary resistive switching oxides and contributing towards developing a unified switching model. Besides finding application as non-volatile memory, RRAM devices are also promising for hardware implementation of neuromorphic computing. This is motivated by the possibility of multi-level switching or gradual (analog) modulation of resistance in an RRAM device which can emulate biological synapses. Defect engineering approaches have thus been investigated in Pt/hafnium oxide/TiN devices for tuning the DC I-V switching dynamics to achieve multi-level or gradual switching electronic synapses. Higher contribution of thermal effects in pure stoichiometric HfO2 typically results in a single sharp set process and abrupt sharp current jumps during the reset process during a conventional bipolar operation. By using ~18% La-doped HfOx based device, a completely gradual reset behavior with a higher ON/OFF ratio could be achieved during the bipolar reset operation. This is likely related to filament stabilization around the dopant sites allowing a uniform rupture during reset. More interestingly, in oxygen deficient HfO1.5 based devices, intermediate conductance states corresponding to integer or half-integer multiples of quantum conductance (G0) was observed during both the set and reset operations at room temperature. These are related to the better stabilization of intermediate atomic size filament constrictions during the switching process. Occurrence of these intermediate quantum conductance states, especially during the typically abrupt set process, is likely aided by a weaker filament and better thermal dissipation in the highly oxygen deficient devices. These results suggest that a combination of doping and high oxygen vacancy concentration may lead to improved synaptic functionality with concurrent gradual set and reset behaviors

Understanding Quantum Technologies 2022

Understanding Quantum Technologies 2022 is a creative-commons ebook that provides a unique 360 degrees overview of quantum technologies from science and technology to geopolitical and societal issues. It covers quantum physics history, quantum physics 101, gate-based quantum computing, quantum computing engineering (including quantum error corrections and quantum computing energetics), quantum computing hardware (all qubit types, including quantum annealing and quantum simulation paradigms, history, science, research, implementation and vendors), quantum enabling technologies (cryogenics, control electronics, photonics, components fabs, raw materials), quantum computing algorithms, software development tools and use cases, unconventional computing (potential alternatives to quantum and classical computing), quantum telecommunications and cryptography, quantum sensing, quantum technologies around the world, quantum technologies societal impact and even quantum fake sciences. The main audience are computer science engineers, developers and IT specialists as well as quantum scientists and students who want to acquire a global view of how quantum technologies work, and particularly quantum computing. This version is an extensive update to the 2021 edition published in October 2021.Comment: 1132 pages, 920 figures, Letter forma

Advancing the Cyberinfrastructure for Smart Water Metering and Water Demand Modeling

With rapid growth of urban populations and limited water resources, achieving an appropriate balance between water supply capacity and residential water demand poses a significant challenge to water supplying agencies. With the recent emergence of smart metering technology, where water use can be monitored and recorded at high resolution (e.g., observations of water use every 5 seconds), most existing research has been aimed at providing water managers with detailed information about the water use behavior of their consumers and the performance of water using fixtures. However, replacing existing meters with smart meters is expensive, and effectively using data produced by smart meters can be a roadblock for water utilities that lack sophisticated information technology expertise. The research in this dissertation presents low cost, open source cyberinfrastructure aimed at addressing these challenges. Components developed include an open source algorithm for identifying and classifying water end use events from smart meter data, a low cost datalogging and computational device that enables existing water meters to collect high resolution data and compute end use information, and a detailed water demand model that uses end use event information to simulate residential water use at a municipality level. Using this cyberinfrastructure, we conducted a case study application in the cities of Logan and Providence, Utah. We tested the applicability of the disaggregation algorithm in quantifying water end uses for different meter sizes and types. We tested the datalogging computational device at a residential household and demonstrated collection, disaggregation, and transfer of high resolution flow data and classified events into a secure server. Finally, we demonstrated a water demand model that simulates the detailed water end uses of Logan’s residents using a combination of a set of representative water end use events and monthly billing data. Using the data we collected and the outputs from the model, we demonstrated opportunities for conserving water through improving the efficiency of water using fixtures and promoting behavior changes