A Technology Aware Magnetic QCA NCL-HDL Architecture

Magnetic Quantum Dot Cellular Automata (MQCA) have been recently proposed as an attractive implementation of QCA as a possible CMOS technology substitute. Marking a difference with respect to previous contributions, in this work we show that it is possible to develop and describe complex MQCA computational blocks strongly linking technology and having in mind a feasible realization. Thus, we propose a practicable clock structure for MQCA baptised "snake-clock", we stick to this while developing a system level Hardware Description Language (HDL) based description of an architectural block, and we suggest a delay insensitive Null Convention Logic (NCL) implementation for the magnetic case so that the "layout=timing" problem can be solved. Furthermore we include in our model aspects critically related to technology and real production, that is timing, power and layout, and we present the preliminary steps of our experiments, the results of which will be included in the architecture descriptio

Rhinoclemmys areolata

Number of Pages: 2Integrative BiologyGeological Science

Magnetic dipolar coupling and collective effects for binary information codification in cost-effective logic devices

Physical limitations foreshadow the eventual end to traditional Complementary Metal Oxide Semiconductor (CMOS) scaling. Therefore, interest has turned to various materials and technologies aimed to succeed to traditional CMOS. Magnetic Quantum dot Cellular Automata (MQCA) are one of these technologies. Working MQCA arrays require very complex techniques and an excellent control on the geometry of the nanomagnets and on the quality of the magnetic thin film, thus limiting the possibility for MQCA of representing a definite solution to cost-effective, high density and low power consumption device demand. Counter-intuitively, moving towards bigger sizes and lighter technologies it is still possible to develop multi-state logicdevices, as we demonstrated, whose main advantage is cost-effectiveness. Applications may be seen in low costlogicdevices where integration and computational power are not the main issue, eventually using flexible substrates and taking advantage of the intrinsic mechanical toughness of systems where long range interactions do not need wirings. We realized cobalt micrometric MQCA arrays by means of Electron Beam Lithography, exploiting cost-effective processes such as lift-off and RF sputtering that usually are avoided due to their low control on array geometry and film roughness. Information relative to the magnetic configuration of MQCA elements including their eventual magnetic interactions was obtained from Magnetic Force Microscope (MFM) images, enhanced by means of a numerical procedure and presented in differential maps. We report the existence of bi-stable magnetic patterns, as detected by MFM while sampling the z-component of magnetic induction field, arising from dipolar inter-element magnetostatic coupling, able to store and propagate binaryinformation. This is achieved despite the array quality and element magnetic state, which are low and multi-domain, respectively. We discuss in detail shape, inter-element spacing and dot profile effects on the magneticcoupling. Numerical Finite Element Method (FEM) simulations show a possible microspin arrangement producing such magnetostatic couplin

Thermally evaporated Cu-Co top spin valve with random exchange bias

A cobalt-copper top spin valve was prepared by thermal evaporation of a stack of ferromagnetic thin films separated by thin layers of the diamagnetic metal, with a cap layer containing an antiferromagnetic AFM exchange-biasing material. A nonconventional top AFM layer was used, in order to optimize the multilayer roughness and to avoid electrical interference with metallic layers; it consists of a composite material easily processed by means of optical lithography, basically a polymeric matrix composite with a dispersion of nickel oxide microparticles. Magnetization and magnetoresistance measurements were performed from 4 to 300 K. The measurements of both quantities indicate random pinning action of the top AFM layer, resulting in a small exchange-bias field and in asymmetric magnetization and magnetoresistance curves. A simple model explains the observed physical effect

Ag nanoparticle-based inkjet printed planar transmission lines for RF and microwave applications: considerations on ink composition, nanoparticle size distribution and sintering time

Sintering of Ag Nanoparticle (NP) - based inkjet printed tracks is a crucial process for the next-generation digitally printed electronics. In particular, while the digital printing, as additive technology, is now well settled for what concerns either DC or signal applications both on rigid and on flexible substrates, this technology has not been demonstrated yet in the RF or microwave field, and a few works appear considering vacuum-evaporated films, screen-printed pastes or inkjet printed inks. We studied the effects of both ink composition and thermal profile on the resulting electrical properties, performing real-time resistance acquisition (DC) and post-annealing microwave measurements. We tested ink compositions featuring both different NP size distributions and different phase compositions, including a pure solvent/salt/metal one and a solvent/salt/metal/polymer one, resulting in a peculiar mass distribution and heat diffusion. The composition strongly affects the onset of electrical percolation and the final resistivity; on the contrary, the heating rate can either have an effect on electrical properties or not depending on the composition. The microwave characterization of microstrip lines printed on alumina substrates, performed up to 26.5 GHz, yield attenuations that are comparable with the best results obtained so far with the same technolog

Liquid Cybernetic Systems: The Fourth‐Order Cybernetics

Technological development in robotics, computing architectures and devices, and information storage systems, in one single word: cybernetic systems, has progressed according to a jeopardized connection scheme, difficult if not impossible to track and picture in all its streams. Aim of this progress report is to critically introduce the most relevant limits and present a promising paradigm that might bring new momentum, offering features that naturally and elegantly overcome current challenges and introduce several other advantages: liquid cybernetic systems. The topic describing the four orders of cybernetic systems identified so far is introduced, evidencing the features of the fourth order that includes liquid systems. Then, current limitations to the development of conventional, von Neumann‐based cybernetic systems are briefly discussed: device integration, thermal design, data throughput, and energy consumption. In the following sections, liquid‐state machines are introduced, providing a computational paradigm (free from in materio considerations) that goes into the direction of solving such issues. Two original in materio implementation schemes are proposed: the COlloIdal demonsTratOR (COgITOR) autonomous robot, and a soft holonomic processor that is also proposed to realize an autolographic system