Information Processing Devices Research Articles

Recent advances in key elements of spin-wave logic gates

Traditional charge-based device development is approaching the limit of Moores law, thus, there is a desperate need for new information processing principles or architectures. Replacing traditional charge-based devices with non-charge-based devices for information processing shows promise. Spin waves, which are generated from the collective precession of electron spins, are thought to be an important information carrier for the transmission and processing of information in a beyond-Moore era. Spin-wave logic gates possess incomparable advantages over traditional logic devices in energy consumption, device scale, application frequency, and logical operation, among other factors. This article explains the operating principles of spin-wave logic gates based on a Mach-Zehnder interferometer structure, and then analyzes the realization theory of key spin-wave logic gate elements at a device level. Recent advances in these key elements are also reviewed systematically. Lastly, future prospects of spin-wave logic gates are discussed.

A Study on the Test Method of Local Information Processing Device in Digital Substation Based on IEC 61850

A Study on the Test Method of Local Information Processing Device in Digital Substation Based on IEC 61850

Integrated 256 Cell Photonic Phase-Change Memory With 512-Bit Capacity

All-optical nonvolatile memories enable storage of telecommunication data without detours through electronic circuitry. Phase-change materials provide the means to embed such memories within integrated optical circuits and thus allow combining waveguide devices for information processing with local data storage. Using this concept, we realize an all-photonic memory circuit capable of storing 512 bits of data in an array of nanoscale phase-change devices. We employ multilevel addressing and wavelength multiplexing of microring resonators to write and read a 16 × 16 greyscale image with 2-bit resolution entirely in the optical domain. Our approach holds promise for implementing scalable architectures for on-chip optical data storage with long data retention and ultrafast access times.

Plasmonics: A Path to Replace Electronics and Photonics by Scalable Ultra-fast Technology

Semiconductor devices, circuits, and components are dependent upon miniaturization for transporting huge amounts of data at a high speed these provide the ability to control the transport and storage of electrons. Current communication systems are based on either electrons or photonics. These modern electronic devices for information processing and sensing are functioning almost close to their fundamental speed and bandwidth limitations which a serious problem. The performance of electronic circuits, as well as photonics, is now becoming rather limited when digital information needs to be sent from one point to another. Plasmonics is a new technology a kind of photonics-based on surface plasmons viable. Surface plasmons are a way of guiding light. Surface Plasmon (SP) based circuits, which merge electronics and photonics at the nanoscale, may offer a solution to the size-compatibility problem. Optical fiber communication (OFC) is a well-known light enabled information transmission mechanism communicates very effectively over large distance. Surface plasmons, on the other hand, can guide light only over distances of tens or hundreds of microns. Surface plasmons are the electromagnetic (optical) waves get generated from the interaction between light and the mobile conduction electrons on the surface of a metal. The surface plasmons created by the interaction of light near the surface possess unique advantages like the high speed of communication which is very essential for the current generation of electrical and medical fields.

Direct Visualization of Local Spin Transition Behaviors in Thin Molecular Films by Bimodal AFM.

Thin films of the molecular spin-crossover complex [Fe(HB(1,2,4-triazol-1-yl)3 )2 ] undergo spin transition above room temperature, which can be exploited in sensors, actuators, and information processing devices. Variable temperature viscoelastic mapping of the films by atomic force microscopy reveals a pronounced decrease of the elastic modulus when going from the low spin (5.2 ± 0.4 GPa) to the high spin (3.6 ± 0.2 GPa) state, which is also accompanied by increasing energy dissipation. This technique allows imaging, with high spatial resolution, of the formation of high spin puddles around film defects, which is ascribed to local strain relaxation. On the other hand, no clustering process due to cooperative phenomena was observed. This experimental approach sets the stage for the investigation of spin transition at the nanoscale, including phase nucleation and evolution as well as local strain effects.

Intrinsic Controllable Magnetism of Graphene Grown on Fe

Novel functional materials that use both the spin and charge of an electron offer many exciting opportunities to create new information processing and storage devices with ultralow power consumptio...

Dynamics of antiskyrmions induced by the voltage-controlled magnetic anisotropy gradient

Magnetic skyrmions could serve as information carriers in next-generation information storage and processing devices. Effective manipulation of the skyrmion motion is a vital task for realizing skyrmion-based applications. Skyrmion motion driven by voltage-controlled magnetic anisotropy (VCMA) has been proposed, of which the investigation is mostly focused on the dynamics of skyrmions. Here, using micromagnetic simulations we show that antiskyrmions can be effectively driven by the VCMA gradient in the presence of the anisotropic Dzyaloshinskii-Moriya interaction. We find that the antiskyrmion shows a transverse motion, i.e., the skyrmion Hall effect, induced by the VCMA gradient. As the skyrmion number of an antiskyrmion is opposite to that of a skyrmion, the anisotropy gradient-induced motion of ferromagnetically coupled skyrmion-antiskyrmion pair and antiferromagnetically coupled skyrmion-skyrmion and antiskyrmion-antiskyrmion pairs do not show the skyrmion Hall effect. We find that the velocity-driving force relations of these three combinations are different. Our results may provide guidelines for building future skyrmion-based information processing applications.

Entanglement of two distant quantum dots with the flip-flop interaction coupled to plasmonic waveguide

The entanglement of two distant quantum dots coupled to metallic waveguide has been investigated theoretically in the presence of the flip-flop interaction with the analytic solutions of eigenvalue equations of the system. High entanglement of two quantum dots could be achieved by adjusting the direct-coupling strength of two quantum dots, the coupling strength of quantum dots with surface plasmon along metallic waveguide, the group velocity of surface plasmon and detuning. The discussed system with the flip-flop interaction provides us with a rich way to realize the quantum device for quantum information processing, such as quantum communication and quantum computation.

Economic Reasoning and Interaction in Socially Extended Market Institutions.

An important part of what it means for agents to be situated in the everyday world of human affairs includes their engagement with economic practices. In this paper, we employ the concept of cognitive institutions in order to provide an enactive and interactive interpretation of market and economic reasoning. We challenge traditional views that understand markets in terms of market structures or as processors of distributed information. The alternative conception builds upon the notion of the market as a “scaffolding institution.” Introducing the concept of market as a “socially extended” cognitive institution we go beyond the notion of scaffolding to provide an enactive view of economic reasoning that understands the market participant in terms of social interactive processes and relational autonomy. Markets are more than inert devices for information processing; they can be viewed as “highly scaffolded,” where strong constraints and incentives predictably direct agents’ behavior. Building on this idea we argue that markets emerge from (a) the economic interaction of both supply and demand sides, in continual and mutual interplay, and (b) more basic social interactions. Consumer behavior in the marketplace is complex, not only contributing to determine the market price, but also extending the consumer’s cognitive processes to reliably attain a correct evaluation of the good. Moreover, this economic reasoning is socially situated and not something done in isolation from other consumers. From a socially situated, interactive point of view buying or not buying a good is something that enacts the market. This shifts the status of markets from external institutions that merely causally affect participants’ cognitive processes to social institutions that constitutively extend these cognitive processes. On this view the constraints imposed by social interactions, as well as the possibilities enabled by such interactions, are such that economic reasoning is never just an individual process carried out by an autonomous individual, classically understood. In this regard, understanding the concept of relational autonomy allows us to see how economic reasoning is always embodied, embedded in, and scaffolded by intersubjective interactions, and how such interactions make the market what it is.

System-environment correlations in qubit initialization and control

The impressive progress in fabricating and controlling superconducting devices for quantum information processing has reached a level where reliable theoretical predictions need to account for quantum correlations that are not captured by the conventional modeling of contemporary quantum computers. This applies particularly to the qubit initialization as the process which crucially limits typical operation times. Here we employ numerically exact methods to study realistic implementations of a transmon qubit embedded in electromagnetic environments focusing on the most important system-reservoir correlation effects such as the Lamb shift and entanglement. For the qubit initialization we find a fundamental trade-off between speed and accuracy which sets intrinsic constraints in the optimization of future reset protocols. Instead, the fidelities of quantum logic gates can be sufficiently accurately predicted by standard treatments. Our results can be used to accurately predict the performance of specific set-ups and also to guide future experiments in probing low-temperature properties of qubit reservoirs.

Magnetic Skyrmion Spectrum Under Voltage Excitation and its Linear Modulation

Magnetic skyrmions are topological quasiparticles with great potential for applications in future information storage and processing devices because of their nanoscale size, high stability, and large velocity. Recently, the high-frequency properties of skyrmions have been explored for magnon nanodevices. Here we systematically study the dynamics of an isolated skyrmion under voltage excitation through the voltage-controlled magnetic anisotropy effect in a circular thin film. A theoretical model considering the demagnetization energy, which has often been neglected or treated superficially in previous skyrmion research but is demonstrated to have importance in determining the skyrmion dynamic state, is developed. With our model, the periodic oscillation of the skyrmion radius can be solved numerically with similar precision compared to micromgnetic simulations, and the characteristic frequency of the skyrmion breathing can be determined analytically with greater precision than previous studies. Furthermore, we find that the breathing skyrmion can be analogized as a modulator by investigating its linear modulation functionality under sinusoidal-form voltage excitation. Different from the conventional modulation system with complex CMOS circuits, this skyrmion modulator device integrates with both the modulation and carrier wave generation functionality, thus showing greater convenience and efficiency in applications. Our findings can provide useful guidance for both theoretical and experimental skyrmions research as well as the development of skyrmion-based magnonic devices with significant potential applicability in future communication system.

Optical Scheme of Obtaining Highest Transmission Factor in Case of KDP Based Electro-Optic Crystal by the Adjustment of Suitable Biasing Voltage and Number of Feedback Passing

Abstract The electro-optic effect becomes prominent when an electric field is applied across the optic axis of a dielectric material inducing the changes in refractive indices of the medium. Kerr and Pockels cells are massively used as optical switches because of their nonlinear electro-optic character. Potassium di-hydrogen Phosphate (KDP) crystal is a very good electro-optic Pockels material as well as has a good switching behavior in optical and opto-electronic domain. The principle of this electro optic effect can be successfully used to develop optical switch based information processing devices. Transmission co-efficient of the polarized light beam have been modulated in a new way by introducing a multi passing scheme across a electro-optic material. Here transmission co-efficient plays a vital role to examine how much output intensity changes for developing feedback one by one in ascending order. In this paper a novel study for the sizable increase of transmission co-efficient of a KDP crystal for a fixed biasing voltage is reported adopting proper feedback mechanism of light. This paper we also observe an theoretical basis for achieving unit transmission coefficient which minimum amount of voltage require for adopting comparatively many large number of feedback.

Thermo-Reversible Hybrid Gels Formed from the Combination of Isotactic Polystyrene and [Fe(II) (4-Octadecyl-1,2,4-Triazole)3(ClO4)2]n Metallo-Organic Polymer: Thermal and Viscoelastic Properties.

Nano-sized one-dimensional metallo-organic polymers, characterized by the phenomenon of spin transition, are excellent candidates for advanced technological applications such as optical sensors, storage, and information processing devices. However, the main drawback of this type of polymers is their fragile mechanical properties, which hinders its processing and handling, and makes their practical use unfeasible. To overcome this problem, in this work, hybrid thermo-reversible gels are synthesized by combination of a metallo-organic polymer and isotactic polystyrene (iPS) in cis-decaline. A detailed investigation of the thermal and viscoelastic properties of the hybrid gels, in terms of iPS and metallo-organic polymer concentration is performed by means of differential scanning calorimetry and oscillatory rheology, respectively. From the analysis of the thermal properties, three transitions have been determined upon heating: Monotectic transition of the iPS gel, melting of the iPS gel, and melting of the metal-organic polymer gel, which suggest that the gels of the two polymers are formed independently in the hybrid gel, as long as the two polymers are in concentrations above the corresponding critical gelation concentrations. Results regarding viscoelastic properties and morphology confirmed that hybrid gels consisted of an interpenetrated network of polymer gels, formed by iPS and metallo-organic poymer gels growing independently.

Colloidal plasmonic DNA-origami with photo-switchable chirality in liquid crystals

Photo-responsive nanomaterials hold great promise for realizing information processing devices, micro-machines, and biosensors. Scalable assembly of such materials using mesostructured liquids, such as liquid crystals, remains a challenge due to the poor compatibility of nanostructures and the host medium. Here we demonstrate a new type of colloidal dispersion of plasmonic DNA-origami with photo-switchable chirality in cellulose nanofiber-based liquid crystals. The composite material inherits properties of DNA-origami plasmonic nanostructures, so that the composite’s chirality can be erased by ultraviolet light and recovered by visible light. The cellulose nanofibers provide a liquid crystalline host with weak optical birefringence, which barely affects the polarization of the incident light, so that the response is dominated by circular dichroism of uniformly dispersed plasmonic nanostructures. Our approach may serve as a new platform for scalable assembling DNA origami-templated nanomaterials.

Are Verbal-Narrative Models More Suitable than Mathematical Models as Information Processing Devices for Some Behavioral (Biosemiotic) Problems?

This article argues that many, if not most, behavior descriptions and sequencing are in essence an interpretation of signs, and are evaluated as sequences of signs by researchers. Thus, narrative analysis, as developed by Barthes and others, seems best suited to be used in behavioral/biosemiotic studies rather than mathematical modeling, and is very similar to some classic ethology methods. As our brain interprets behaviors as signs and attributes meaning to them, narrative analysis seems more suitable than mathematical modeling to describe and study behavior. Mathematical models are, on many occasions, extremely reductionist and simplifying because of computational and/or numerical representation limitations that lead to errors and straitjacketing interpretations of reality. Since actual animals (and our analysis of their behavior) are not as optimal in real life as our mathematical models, here it is proposed that we should consider logical/verbal models and semantic interpretations as equally or even better suited for behavioral analysis, and refrain from enforcing mathematical modeling as the only (right) way to study and understand biological problems, especially those of a behavioral and biosemiotic nature.

Near-Unity Indistinguishability Single Photon Source for Large-Scale Integrated Quantum Optics.

Integrated single photon sources are key building blocks for realizing scalable devices for quantum information processing. For such applications highly coherent and indistinguishable single photons on a chip are required. Here we report on a triggered resonance fluorescence single photon source based on In(Ga)As/GaAs quantum dots coupled to single- and multimode ridge waveguides. We demonstrate the generation of highly linearly polarized resonance fluorescence photons with 99.1% (96.0%) single photon purity and 97.5% (95.0%) indistinguishability in case of multimode (single mode) waveguide devices fulfilling the strict requirements imposed by multi-interferometric quantum optics applications. Our integrated triggered single photon source can be readily scaled up, promising a realistic pathway for on-chip linear optical quantum simulation, quantum computation, and quantum networks.

Synthetic spin\u2013orbit coupling and topological polaritons in Janeys\u2013Cummings lattices

The interaction between a photon and a qubit in the Janeys–Cummings (JC) model generates a kind of quasiparticle called polariton. While they are widely used in quantum optics, difficulties in engineering-controllable coupling of them severely limit their applications to simulate spinful quantum systems. Here we show that, in the superconducting quantum circuit context, polariton states in the single-excitation manifold of a JC lattice can be used to simulate a spin-1/2 system, based on which tunable synthetic spin–orbit coupling and novel topological polaritons can be generated and explored. The lattice is formed by a sequence of coupled transmission line resonators, each of which is connected to a transmon qubit. Synthetic spin–orbit coupling and the effective Zeeman field of the polariton can both be tuned by modulating the coupling strength between neighboring resonators, allowing for the realization of a large variety of polaritonic topological semimetal bands. Methods for detecting the polaritonic topological edge states and topological invariants are also proposed. Therefore, our work suggests that the JC lattice is a versatile platform for exploring spinful topological states of matter, which may inspire developments of topologically protected quantum optical and information-processing devices.

Quantum tomography of the photon-plasmon conversion process in a metal hole array

In the past decades, quantum plasmonics has become an active area due to its potential applications in on-chip plasmonic devices for quantum information processing. However, the fundamental physical process, i.e., how a quantum state of light evolves in the photon-plasmon conversion process, has not been described by a detailed microscopic quantum model. Here, we report a complete characterization of the plasmon-assisted extraordinary optical transmission process through quantum process tomography. By inputting various coherent states to interact with the plasmonic structure and detecting the output states with a homodyne detector, we reconstruct the process tensor of the photon-plasmon conversion process. Both the amplitude and phase information of the process are extracted, which explain the evolution of the quantum-optical state after the coupling with plasmons. Our experimental demonstration constitutes a fundamental block for future on-chip applications of quantum plasmonic circuits.

Tomographic reconstruction of multiqubit states by phase lift with the Nesterov algorithm

Quantum state tomography is of crucial importance in assessing the quality of quantum information processing devices. Tomography fundamentally requires both experiments and data processing resources, which increase exponentially with the size of qubits. We propose using phase lift to precisely characterize an unknown quantum state using only a small part of the data. We numerically reconstruct the density matrix of multiqubit pure states including the Greenberger-Horne-Zeilinger (GHZ) state, W-class state, cluster state, and random states. The Nesterov algorithm shows high accuracy and high speed for pure states especially for the specific entangled states with a large number of qubits. It shows the highest accuracy among the several specific algorithms, specially for larger number of qubits.

Magnetic III-N Semiconductors Based on Rare Earth Doping

This paper focuses on the magnetic properties of wide bandgap III-N semiconductors doped with rare earth elements. Such materials form a novel class of dilute magnetic semiconductors that have an important potential impact on future information processing devices. In particular, rare earth doped III-N thin films may lead to integration of electronic, optical, and magnetic functionality for computation, sensing, and communication applications. The main aspects of this paper concern the efficient incorporation of rare earth ions in III-N thin films and the demonstration of magnetic effects at room temperature. While early studies were based on ion implantation and solid-state diffusion, major advances have been achieved through molecular beam epitaxy and metal-organic chemical vapor deposition. Measurements of room temperature magnetic effects from III-N films doped with rare earth elements, including erbium, gadolinium, and europium, are presented. The dependence of measured magnetic properties on the synthesis method and co-doping are addressed.