Littérature scientifique sur le sujet « Nano Magnetic Logic »

Abstract Bit manipulation plays a significant role in high-speed digital signal processing (DSP) and data computing systems, and shift and rotation operations are crucial functions in it. In general, barrel shifters are used to perform these operations effectively. Nano magnetic logic circuits are among the promising beyond-CMOS alternative technologies for the design of high-speed circuits. Most of the existing circuits that have been developed using nano magnets are combinational circuits. In this work, a barrel shifter is implemented and realised using in-plane nano magnetic logic. The proposed design is the first of its kind nano magnetic logic circuit. The nano magnetic logic circuit implementation, layout generation, simulation, and validation were performed using the ToPoliNano and ModelSim tools. The logical equivalent design was synthesised and evaluated using the Synopsys Design Compiler tool. The proposed barrel shifter was realised using majority logic has 1769037 nano magnets with a boxing area of 481 × 13104 µm2 and 3276 clock zones after optimisation with the Barycenter algorithm. The proposed barrel shifter realised using Boolean logic has 315276 nano magnets with a boxing area of 265 × 5028 µm2 and 1257 clock zones after optimisation with the Barycenter algorithm. The proposed design results demonstrate that complex systems can be developed using nano magnetic logic by combining combinational and sequential circuits.

Magnetic skyrmion, a nano-sized spin texture with topological property, have the potential to develop high-density, low-power, and multifunctional spintronic devices. To realize the reconfiguration of a single logic device and the implementation of the complete logic functions, a new reconfigurable and reusable skyrmion logic is proposed and verified by micromagnetic simulation. Logic functions including AND, OR, NOT, NAND and NOR are realized in ferromagnetic (FM) nanotrack by skyrmion-edge repulsions and the voltage control of magnetic anisotropy (VCMA) effect. The working state of the potential well can be controlled by the link of the input signals, thus changing the function type. In addition, through reusing skyrmion in circular track, the energy required for creation and deletion is reduced. This work can provide guidance for the design and optimization of reconfigurable and reusable logic devices with circular track based on skyrmion.

Purpose Owing to recent challenges of CMOS manufacturing and power consumption in silicon technologies among alternative technologies, Nanomagnetic logic (NML) is one of the most promising technologies, so it was selected for this study. NML is non-volatile with ultra-low power dissipation that operates at room temperature. This paper aims to propose novel implementation of 2% and 4% multiplexers (MUXs) in NML technology. Design/methodology/approach The proposed multiplexers in NML technology are verified by HDL-based simulators. In addition, this study estimated area and power dissipation of the proposed design to compare and approve the promising improvements in comparison to other similar NML implementations. Findings The results show the remarkable improvements in terms of APDP term in comparison to the recent proposed MUXs in NML technology which are reported in Table 2. The proposed implementation of the MUX in NML is designed in three-dimensional layout to improve interconnection complexity which is an integration challenge. Also, by facilitating the routing signals and total wire length needed for clock signals, the negative impact of the power dissipated in clock wires is improved. Originality/value These findings would appeal to a broad audience, such as the readership of Microelectronics International Journal. The authors confirm that this work is original and has not been published elsewhere nor is it currently under consideration for publication elsewhere. All authors have approved the paper and agreed with submission to Microelectronics International Journal. The authors have read and have abided by the statement of ethical standards for manuscripts submitted to Microelectronics International Journal. The authors have no conflict of interest to declare.

In this paper an ultra-compact all-optical encoder is presented by using a two-dimensional photonic crystal. The designed logic gate is based on the interference effect. The proposed structure consists of several photonic crystal waveguides connected by 2 nano-resonators. The nano-resonators are designed to reduce the size of the radius of the dielectric rods. The contrast ratios and delay time for the proposed all-optical encoder are respectively 6 dB and 125 fs. The size of the structure is equal to 132 µm2. Equality of the output power in the logic states “one”, the small dimensions, the low delay time, compact and simple structure have shown that the logic gate is suitable for the using in optical integrated circuits. Full Text: PDF ReferencesA. Salmanpour, Sh. Mohammadnejad, A. Bahrami, "Photonic crystal logic gates: an overview", Optical and Quantum Electronics. 47, 2249 (2015). CrossRef S. C. Xavier, B. E. Carolin, A. p. Kabilan, W. Johnson, "Compact photonic crystal integrated circuit for all-optical logic operation", IET Optoelectronics. 10, 142 (2016). CrossRef Y. Miyoshi, K. Ikeda, H. Tobioka, T. Inoue, S. Namiki, K. Kitayama, "Ultrafast all-optical logic gate using a nonlinear optical loop mirror based multi-periodic transfer function", Optics Express. 16, 2570 (2008). CrossRef D. K. Gayen, A. Bhattachryya, T. Chattopadhyay, J. N. Roy, "Ultrafast All-Optical Half Adder Using Quantum-Dot Semiconductor Optical Amplifier-Based Mach-Zehnder Interferometer", Journal of Lightwave Technology. 30, 3387 (2012). CrossRef A. Mohebzadeh-Bahabady, S. Olyaee, "All-optical NOT and XOR logic gates using photonic crystal nano-resonator and based on an interference effect", IET Optoelectronics. 12, 191 (2018). CrossRef Z. Mohebbi, N. Nozhat, F. Emami, "High contrast all-optical logic gates based on 2D nonlinear photonic crystal", Optics Communications. 355, 130 (2015). CrossRef M. Mansouri-Birjandi, M. Ghadrdan, "Full-optical tunable add/drop filter based on nonlinear photonic crystal ring resonators", Photonics and Nanostructures-Fundamentals and Applications. 21, 44 (2016). CrossRef H. Alipour-Banaei, S. Serajmohammadi, F. Mehdizadeh, "Effect of scattering rods in the frequency response of photonic crystal demultiplexers", Journal of Optoelectronics and Advanced Materials. 17, 259 (2015). DirectLink A. Mohebzadeh-Bahabady, S. Olyaee, H. Arman, "Optical Biochemical Sensor Using Photonic Crystal Nano-ring Resonators for the Detection of Protein Concentration", Current Nanoscience. 13, 421 (2017). CrossRef S. Olyaee, A. Mohebzadeh-Bahabady, "Designing a novel photonic crystal nano-ring resonator for biosensor application", Optical and Quantum Electronics. 47, 1881 (2015). CrossRef F. Parandin, R. Malmir, M. Naseri, A. Zahedi, "Reconfigurable all-optical NOT, XOR, and NOR logic gates based on two dimensional photonic crystals", Superlattices and Microstructures. 113, 737 (2018). CrossRef F. Mehdizadeh, M. Soroosh, H. Alipour-Banaei, "Proposal for 4-to-2 optical encoder based on photonic crystals", IET Optoelectronics. 11, 29 (2017). CrossRef M. Hassangholizadeh-Kashtiban, R. Sabbaghi-Nadooshan, H. Alipour-Banaei, "A novel all optical reversible 4 × 2 encoder based on photonic crystals", Optik. 126, 2368 (2015). CrossRef T. A. Moniem, "All-optical digital 4 × 2 encoder based on 2D photonic crystal ring resonators", Journal of Modern Optics. 63, 735 (2016). CrossRef S. Gholamnejad, M. Zavvari, "Design and analysis of all-optical 4–2 binary encoder based on photonic crystal", Optical and Quantum Electronics. 49, 302 (2017). CrossRef H. Seif-Dargahi, "Ultra-fast all-optical encoder using photonic crystal-based ring resonators", Photonic Network Communications. 36, 272 (2018). CrossRef S. Olyaee, M. Seifouri, A. Mohebzadeh-Bahabady, and M. Sardari, "Realization of all-optical NOT and XOR logic gates based on interference effect with high contrast ratio and ultra-compacted size", Optical and Quantum Electronics. 50, 12 (2018). CrossRef C. J. Wu, C. P. Liu, Z. Ouyang, "Compact and low-power optical logic NOT gate based on photonic crystal waveguides without optical amplifiers and nonlinear materials", Applied Optics.51, 680 (2012). CrossRef Y. C. Jiang, S. B. Liu, H. F. Zhang, X. K. Kong. "Realization of all optical half-adder based on self-collimated beams by two-dimensional photonic crystals", Optics Communications. 348, 90 (2015). CrossRef A. Salmanpour, S. Mohammadnejad, P. T. Omran, "All-optical photonic crystal NOT and OR logic gates using nonlinear Kerr effect and ring resonators", Optical and Quantum Electronics. 47, 3689 (2015). CrossRef E. H. Shaik, N. Rangaswamy, "Single photonic crystal structure for realization of NAND and NOR logic functions by cascading basic gates", Journal of Computational Electronics. 17, 337 (2018). CrossRef

The following dissertation addresses the study of nano-magnetic devices configured to produce logic machines through magnetostatic coupling interactions. The ability for single domain magnets to reliably couple through magnetostatic interactions is essential to the proper functionality of Magnetic Cellular Automata (MCA) devices (p. 36). It was significant to explore how fabrication defects affected the coupling reliability of MCA architectures. Both ferromagnetic and anti-ferromagnetic coupling architectures were found to be robust to common fabrication defects. Experiments also verified the functionality of the previously reported MCA majority gate [1] and a novel implementation of a ferromagnetic MCA majority gate is reported. From these results, the study of clocking Magnetic Cellular Automata (MCA) interconnect architectures was investigated (p. 54). The wire architectures were saturated under distinct directions of an external magnetic field. The experimental results suggested ferromagnetic coupled wires were able to mitigate magnetic frustrations better than anti-ferromagnetic coupled wires. Simulations were also implemented supporting the experimental results. Ferromagnetic wires were found to operate more reliably and will likely be the primary interconnects for MCA. The first design and implementation of a coplanar cross wire system for MCA was constructed which consisted of orthogonal ferromagnetic coupled wires (p. 68). Simulations were implemented of a simple crossing wire junction to analyze micro-magnetic dynamics, data propagation, and associated energy states. Furthermore, two systems were physically realized; the first system consisted of two coplanar crossing wires and the second was a more complex system consisting of over 120 nano-magnetic cells. By demonstrating the combination of all the possible logic states of the first system and the low ground state achieved by the second system, the data suggested coplanar cross wire systems would indeed be a viable architecture in MCA technology. Finally, ongoing research of an unconventional method for image processing using nano-magnetic field-based computation is presented (p. 79). In magnetic field-based computing (MFC), nano-disks were mapped to low level segments of an image, and the magnetostatic coupling of magnetic dipole moments was directly related to the saliency of a low level segment for grouping. A proof of concept model for two MFC systems was implemented. Details such as the importance of fabricating circular nano-magnetic cells to mitigate shape anisotropy, experimental coupling analysis via Magnetic Force Microscopy, and current results from a complex MFC system is outlined.

The continuous scaling down of the metal-oxide-semiconductor field-effect transistor (MOSFET) has improved the performance of electronic appliances. Unfortunately, it has come to a stage where further scaling of the MOSFET is no longer possible due to the physical and the fabrication limitations. This has motivated researchers towards designing and fabricating novel devices that can replace MOSFET technology. Carbon Nanotube Field-Effect Transistors, Single Electron Tunneling Junctions, Nano-Magnetic Devices, and Spin Field-Effect Transistors are some prospective candidates that could replace MOSFET devices. In this dissertation, we have studied the computational performance of Nano−Magnetic Devices due to their attractive features such as room temperature operation, high density, robustness towards thermal noise, radiation hardened nature and low static power dissipation. In this work, we have established that data can be propagated in a causal fashion from a driver cell to the driven cells. We have fabricated a ferromagnetic wire architecture and used a magnetic force microscopy (MFM) tip to provide localized magnetic inputs. This experiment validated two important phenomena; (1) a clocking field is essential to propagate data and (2) upon removal of the clocking field data can be propagated according to the input data. Next, we have fabricated and captured MFM images of a nano-magnetic logic architecture that has computed the majority of seven binary variables. The architecture was designed by interconnecting three three-input majority logic gates with ferromagnetic and antiferromagnetic wire architectures. This seven input majority logic architecture can potentially implement eight different logic functions that could be configured in real-time. All eight functions could be configured by three control parameters in real-time (by writing logic one or zero to them). Even though we observed error-free operations in nano-magnetic logic architectures, it became clear that we needed better control (write/read/clock) over individual single layer nano-magnetic devices for successful long-term operation. To address the write/clock/read problems, we designed and fabricated amultilayer nano-magnetic device. We fabricated and performed a set of experiments with patterned multilayer stacks of Co/Cu/Ni80Fe20 with a bottom layer having a perpendicular magnetization to realize neighbor interactions between adjacent top layers of devices. Based on the MFM images, we conclude that dipolar coupling between the top layers of the neighboring devices can be exploited to construct three-input majority logic gates, antiferromagnetic and ferromagnetic wire architectures. Finally, we have experimentally demonstrated a magnetic system that could be used to solve quadratic optimization problems that arise in computer vision applications. We have harnessed the energy minimization nature of a magnetic system to directly solve a quadratic optimization process. We have fabricated a magnetic system corresponding to a real world image and have identified salient features with true positive rate more than 85%. These experimental results feature the potentiality of this unconventional computing method to develop a magnetic processor which solves such complex problems in few clock cycles.

Magnetic nanoscale devices have shown great promise in both research and industry. Magnetic nanostructures have potential for non-volatile data storage applications, reconfigurable logic devices, biomedical devices and many more. The S-state magnetic element is one of the promising structures for non-volatile data storage applications and reconfigurable logic devices. It is a single-layer logic element that can be integrated in magnetoresistive structures. We present a detailed micromagnetic analysis of the geometrical parameter space in which the logic operation is carried out. The influence of imperfections, such as sidewall roughness and roundness of the edge is investigated. Magnetic nanowires are highly attractive materials that has potential for applications in ultrahigh magnetic recording, logic operation devices, and micromagnetic and spintronic sensors. To utilize applications, manipulation and assembly of nanowires into ordered structures is needed. Magnetic self-alignment is a facile technique for assembling nanowires into hierarchical structures. In my thesis, I focus on synthesizing and assembling nickel nanowires. The magnetic behaviour of a single nickel nanowire with 200~nm diameter is investigated in micromagnetic simulations. Nickel nanowires with Au caps at the ends were synthesized by electrochemical deposition into nanopores in alumina templates. One-dimensional alignment, which forms chains and two-dimensional alignment, which forms T-junctions as well as cross-junctions are demonstrated. Attempts to achieve three-dimensional alignment were not successful yet. I will discuss strategies to improve the alignment process.