Journal articles: 'Artificial spin systems'

1

Lammert, Paul E., Vincent H. Crespi, and Cristiano Nisoli. "Gibbsianizing nonequilibrium dynamics of artificial spin ice and other spin systems." New Journal of Physics 14, no. 4 (April 19, 2012): 045009. http://dx.doi.org/10.1088/1367-2630/14/4/045009.

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Panagiotopoulos, I. "Magnetostatic bias in Kagome artificial spin ice systems." Physica B: Condensed Matter 486 (April 2016): 21–23. http://dx.doi.org/10.1016/j.physb.2015.09.007.

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King, Andrew D., Cristiano Nisoli, Edward D. Dahl, Gabriel Poulin-Lamarre, and Alejandro Lopez-Bezanilla. "Qubit spin ice." Science 373, no. 6554 (July 15, 2021): 576–80. http://dx.doi.org/10.1126/science.abe2824.

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Artificial spin ices are frustrated spin systems that can be engineered, in which fine tuning of geometry and topology has allowed the design and characterization of exotic emergent phenomena at the constituent level. Here, we report a realization of spin ice in a lattice of superconducting qubits. Unlike conventional artificial spin ice, our system is disordered by both quantum and thermal fluctuations. The ground state is classically described by the ice rule, and we achieved control over a fragile degeneracy point, leading to a Coulomb phase. The ability to pin individual spins allows us to demonstrate Gauss’s law for emergent effective monopoles in two dimensions. The demonstrated qubit control lays the groundwork for potential future study of topologically protected artificial quantum spin liquids.

4

Garliauskas, A. "Nonlinearities in Artificial Neural Systems Interpreted as an Application of Ising Physics." Nonlinear Analysis: Modelling and Control 11, no. 4 (November 1, 2006): 367–83. http://dx.doi.org/10.15388/na.2006.11.4.14739.

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In this review, the nonlinearities in different processes such as spin glasses, finite field models, Hamiltonian functions, learning and storing capabilities, mean field systems and others in the area of physics related to the artificial neural networks namely the main brain structure interpreted as Ising spin systems are discussed. It is shown that nonlinearities serve as exclusive role in the applied physics field.

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Vanstone, Alex, Jack C. Gartside, Kilian D. Stenning, Troy Dion, Daan M. Arroo, and Will R. Branford. "Spectral fingerprinting: microstate readout via remanence ferromagnetic resonance in artificial spin ice." New Journal of Physics 24, no. 4 (April 1, 2022): 043017. http://dx.doi.org/10.1088/1367-2630/ac608b.

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Abstract Artificial spin ices (ASIs) are magnetic metamaterials comprising geometrically tiled strongly-interacting nanomagnets. There is significant interest in these systems spanning the fundamental physics of many-body systems to potential applications in neuromorphic computation, logic, and recently reconfigurable magnonics. Magnonics focused studies on ASI have to date have focused on the in-field GHz spin-wave response, convoluting effects from applied field, nanofabrication imperfections (‘quenched disorder’) and microstate-dependent dipolar field landscapes. Here, we investigate zero-field measurements of the spin-wave response and demonstrate its ability to provide a ‘spectral fingerprint’ of the system microstate. Removing applied field allows deconvolution of distinct contributions to reversal dynamics from the spin-wave spectra, directly measuring dipolar field strength and quenched disorder as well as net magnetisation. We demonstrate the efficacy and sensitivity of this approach by measuring ASI in three microstates with identical (zero) magnetisation, indistinguishable via magnetometry. The zero-field spin-wave response provides distinct spectral fingerprints of each state, allowing rapid, scaleable microstate readout. As artificial spin systems progress toward device implementation, zero-field functionality is crucial to minimize the power consumption associated with electromagnets. Several proposed hardware neuromorphic computation schemes hinge on leveraging dynamic measurement of ASI microstates to perform computation for which spectral fingerprinting provides a potential solution.

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Li, Jianhua, Wen-Bing Xu, Wen-Cheng Yue, Zixiong Yuan, Tan Gao, Ting-Ting Wang, Zhi-Li Xiao, et al. "Writable spin wave nanochannels in an artificial-spin-ice-mediated ferromagnetic thin film." Applied Physics Letters 120, no. 13 (March 28, 2022): 132404. http://dx.doi.org/10.1063/5.0085455.

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Magnonics, which employs spin-waves to transmit and process information, is a promising venue for low-power data processing. One of the major challenges is the local control of the spin-wave propagation path. Here, we introduce the concept of writable magnonics by taking advantage of the highly flexible reconfigurability and rewritability of artificial spin ice systems. Using micromagnetic simulations, we show that globally switchable spin-wave propagation and locally writable spin-wave nanochannels can be realized in a ferromagnetic thin film underlying an artificial pinwheel spin ice. The rewritable magnonics enabled by reconfigurable spin wave nanochannels provides a unique setting to design programmable magnonic circuits and logic devices for ultra-low power applications.

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Rodrigues, J. H., and L. A. S. Mól. "Towards magnetic monopole interaction measurement in artificial spin ice systems." Journal of Magnetism and Magnetic Materials 458 (July 2018): 327–34. http://dx.doi.org/10.1016/j.jmmm.2018.03.032.

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Pip, Petai, Samuel Treves, Jamie R. Massey, Simone Finizio, Zhaochu Luo, Aleš Hrabec, Valerio Scagnoli, et al. "X-ray imaging of the magnetic configuration of a three-dimensional artificial spin ice building block." APL Materials 10, no. 10 (October 1, 2022): 101101. http://dx.doi.org/10.1063/5.0101797.

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The extension of artificial spin systems to the third dimension offers advances in functionalities and opportunities for technological applications. One of the main challenges facing their realization is the fabrication of three-dimensional geometries with nanoscale resolution. In this work, we combine two-photon lithography with deformation-free pyrolysis and a GdCo coating to create a three-dimensional (3D) tripod structure that represents a building block of an 3D artificial spin ice, surrounded by a two-dimensional magnetic film. We map the three-dimensional magnetic configuration of the structure and its surroundings using soft x-ray magnetic laminography. In this way, we determine the magnetic configuration of the tripod nanostructure to be in the low-energy two-in-one-out spin ice state, observed at the 2D vertex of a kagome ice and predicted for three-dimensional vertices of magnetic buckyball structures. In contrast to isolated vertices, the degeneracy of this state can be lifted by the surrounding film, which also offers a route toward the controlled injection of emergent charges. This demonstration of the building block of a 3D spin system represents the first step toward the realization and understanding of more complex 3D artificial spin systems.

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Rechcińska, Katarzyna, Mateusz Król, Rafał Mazur, Przemysław Morawiak, Rafał Mirek, Karolina Łempicka, Witold Bardyszewski, et al. "Engineering spin-orbit synthetic Hamiltonians in liquid-crystal optical cavities." Science 366, no. 6466 (November 7, 2019): 727–30. http://dx.doi.org/10.1126/science.aay4182.

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Spin-orbit interactions lead to distinctive functionalities in photonic systems. They exploit the analogy between the quantum mechanical description of a complex electronic spin-orbit system and synthetic Hamiltonians derived for the propagation of electromagnetic waves in dedicated spatial structures. We realize an artificial Rashba-Dresselhaus spin-orbit interaction in a liquid crystal–filled optical cavity. Three-dimensional tomography in energy-momentum space enabled us to directly evidence the spin-split photon mode in the presence of an artificial spin-orbit coupling. The effect is observed when two orthogonal linear polarized modes of opposite parity are brought near resonance. Engineering of spin-orbit synthetic Hamiltonians in optical cavities opens the door to photonic emulators of quantum Hamiltonians with internal degrees of freedom.

10

Gust, Devens. "Supramolecular photochemistry applied to artificial photosynthesis and molecular logic devices." Faraday Discussions 185 (2015): 9–35. http://dx.doi.org/10.1039/c5fd00142k.

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Supramolecular photochemical systems consist of photochemically active components such as chromophores, electron donors or electron acceptors that are associated via non-covalent or covalent interactions and that interact in some functional way. Examples of interactions are singlet–singlet energy transfer, triplet–triplet energy transfer, photoinduced electron transfer, quantum coherence and spin–spin magnetic interactions. Supramolecular photochemical “devices” may have applications in areas such as solar energy conversion, molecular logic, computation and data storage, biomedicine, sensing, imaging, and displays. This short review illustrates supramolecular photochemistry with examples drawn from artificial photosynthesis, molecular logic, analog photochemical devices and models for avian magnetic orientation.

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Liu, Peng, Hangyu Li, Zhitao Zhou, and Yongmao Pei. "Topological acoustic tweezer and pseudo-spin states of acoustic topological insulators." Applied Physics Letters 120, no. 22 (May 30, 2022): 222202. http://dx.doi.org/10.1063/5.0091755.

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Topological protection wave engineering in artificially structured media is at the forefront of metamaterials research. Acoustic analogs of electronic topological insulators have brought a lot of new opportunities for manipulating sound propagation and have attracted the attention of many scholars. A variety of artificial acoustic systems hosting topological edge states have been proposed. However, the pseudo-spin edge states at a boundary have not been clearly and intuitively characterized. In this article, we provide experimental verification of pseudo-spin states by the method of acoustic particle manipulation by using the rotation of the particle to describe the pseudo-spin sound field characteristics at the boundary of the acoustic topological insulator in detail. It indicates the existence of pseudo-spin–orbit coupling effects and pseudo-spin-related acoustic unidirectional transmission even if the defect exists. Furthermore, the pseudo-spin sound field can be used to control the rotation of multiple particles and droplets. This kind of topological acoustic tweezer with defect immunity has great application potential in the fields of biomedicine and materials science.

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Shi, Yifei, Cristiano Nisoli, and Gia-Wei Chern. "Ice, glass, and solid phases in artificial spin systems with quenched disorder." Applied Physics Letters 118, no. 12 (March 22, 2021): 122407. http://dx.doi.org/10.1063/5.0046083.

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Begum Popy, Rehana, Julia Frank, and Robert L. Stamps. "Magnetic field driven dynamics in twisted bilayer artificial spin ice at superlattice angles." Journal of Applied Physics 132, no. 13 (October 7, 2022): 133902. http://dx.doi.org/10.1063/5.0118078.

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Geometrical designs of interacting nanomagnets have been studied extensively in the form of two-dimensional arrays called artificial spin ice. These systems are usually designed to create geometrical frustration and are of interest for the unusual and often surprising phenomena that can emerge. Advanced lithographic and element growth techniques have enabled the realization of complex designs that can involve elements arranged in three dimensions. Using numerical simulations employing the dumbbell approximation, we examine possible magnetic behaviors for bilayer artificial spin ice, in which the individual layers are rotated with respect to one another. The goal is to understand how magnetization dynamics are affected by long-range dipolar coupling that can be modified by varying the layer separation and layer alignment through rotation. We consider bilayers where the layers are both either square or pinwheel arrangements of islands. Magnetic reversal processes are studied and discussed in terms of domain and domain wall configurations of the magnetic islands. Unusual magnetic ordering is predicted for special angles that define lateral spin superlattices for the bilayer systems.

14

Farhan, A., P. M. Derlet, A. Kleibert, A. Balan, R. V. Chopdekar, M. Wyss, L. Anghinolfi, F. Nolting, and L. J. Heyderman. "Exploring hyper-cubic energy landscapes in thermally active finite artificial spin-ice systems." Nature Physics 9, no. 6 (May 5, 2013): 375–82. http://dx.doi.org/10.1038/nphys2613.

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15

Farhan, Alan, Michael Saccone, Charlotte F. Petersen, Scott Dhuey, Rajesh V. Chopdekar, Yen-Lin Huang, Noah Kent, et al. "Emergent magnetic monopole dynamics in macroscopically degenerate artificial spin ice." Science Advances 5, no. 2 (February 2019): eaav6380. http://dx.doi.org/10.1126/sciadv.aav6380.

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Magnetic monopoles, proposed as elementary particles that act as isolated magnetic south and north poles, have long attracted research interest as magnetic analogs to electric charge. In solid-state physics, a classical analog to these elusive particles has emerged as topological excitations within pyrochlore spin ice systems. We present the first real-time imaging of emergent magnetic monopole motion in a macroscopically degenerate artificial spin ice system consisting of thermally activated Ising-type nanomagnets lithographically arranged onto a pre-etched silicon substrate. A real-space characterization of emergent magnetic monopoles within the framework of Debye-Hückel theory is performed, providing visual evidence that these topological defects act like a plasma of Coulomb-type magnetic charges. In contrast to vertex defects in a purely two-dimensional artificial square ice, magnetic monopoles are free to evolve within a divergence-free vacuum, a magnetic Coulomb phase, for which features in the form of pinch-point singularities in magnetic structure factors are observed.

16

Hügli, R. V., G. Duff, B. O'Conchuir, E. Mengotti, A. Fraile Rodríguez, F. Nolting, L. J. Heyderman, and H. B. Braun. "Artificial kagome spin ice: dimensional reduction, avalanche control and emergent magnetic monopoles." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 370, no. 1981 (December 28, 2012): 5767–82. http://dx.doi.org/10.1098/rsta.2011.0538.

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Artificial spin-ice systems consisting of nanolithographic arrays of isolated nanomagnets are model systems for the study of frustration-induced phenomena. We have recently demonstrated that monopoles and Dirac strings can be directly observed via synchrotron-based photoemission electron microscopy, where the magnetic state of individual nanoislands can be imaged in real space. These experimental results of Dirac string formation are in excellent agreement with Monte Carlo simulations of the hysteresis of an array of dipoles situated on a kagome lattice with randomized switching fields. This formation of one-dimensional avalanches in a two-dimensional system is in sharp contrast to disordered thin films, where avalanches associated with magnetization reversal are two-dimensional. The self-organized restriction of avalanches to one dimension provides an example of dimensional reduction due to frustration. We give simple explanations for the origin of this dimensional reduction and discuss the disorder dependence of these avalanches. We conclude with the explicit demonstration of how these avalanches can be controlled via locally modified anisotropies. Such a controlled start and stop of avalanches will have potential applications in data storage and information processing.

17

Zhu, Wei, Ruisheng Yang, Guangzhou Geng, Yuancheng Fan, Xuyue Guo, Peng Li, Quanhong Fu, Fuli Zhang, Changzhi Gu, and Junjie Li. "Titanium dioxide metasurface manipulating high-efficiency and broadband photonic spin Hall effect in visible regime." Nanophotonics 9, no. 14 (August 6, 2020): 4327–35. http://dx.doi.org/10.1515/nanoph-2020-0290.

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AbstractThe interactions of photonic spin angular momentum and orbital angular momentum, i.e., the spin-orbit coupling in focused beams, evanescent waves or artificial photonic structures, have attracted intensive investigations for the unusual fundamental phenomena in physics and potential applications in optical and quantum systems. It is of fundamental importance to enhance performance of spin-orbit coupling in optics. Here, we demonstrate a titanium dioxide (TiO2)–based all-dielectric metasurface exhibiting a high efficient control of photonic spin Hall effect (PSHE) in a transmissive configuration. This metasurface can achieve high-efficiency symmetric spin-dependent trajectory propagation due to the spin-dependent Pancharatnam-Berry phase. The as-formed metadevices with high-aspect-ratio TiO2 nanofins are able to realize (86%, measured at 514 nm) and broadband PSHEs in visible regime. Our results provide useful insights on high-efficiency metasurfaces with versatile functionalities in visible regime.

18

Cheenikundil, Rajgowrav, Julien Bauer, Mehrdad Goharyan, Massimiliano d’Aquino, and Riccardo Hertel. "High-frequency modes in a magnetic buckyball nanoarchitecture." APL Materials 10, no. 8 (August 1, 2022): 081106. http://dx.doi.org/10.1063/5.0097695.

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Artificially fabricated three-dimensional magnetic nanostructures have recently emerged as a new type of magnetic material with the potential of displaying physical properties absent in thin-film geometries. Interconnected nanowire arrays yielding three-dimensional versions of artificial spin-ices are of particular interest within this material category. Despite growing interest in the topic, several properties of these systems are still unexplored. Here, we study, through micromagnetic simulations, the high-frequency dynamic modes developing in buckyball-type magnetic nanoarchitectures. We obtain a characteristic excitation spectrum and analyze the corresponding mode profiles and their magnetic field dependence. The magnetic resonances are localized at different geometric constituents of the structure and depend on the local magnetic configuration. These features foreshow the potential of such systems for reprogrammable magnonic device applications with geometrically tunable frequencies.

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Wang, Zhuo, Sixun Liu, Ruigang Wang, Linlin Yuan, Jiong Huang, Yueyang Zhai, and Sheng Zou. "Atomic Spin Polarization Controllability Analysis: A Novel Controllability Determination Method for Spin-Exchange Relaxation-Free Co-Magnetometers." IEEE/CAA Journal of Automatica Sinica 9, no. 4 (April 2022): 699–708. http://dx.doi.org/10.1109/jas.2021.1004383.

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Banerjee-Ghosh, Koyel, Oren Ben Dor, Francesco Tassinari, Eyal Capua, Shira Yochelis, Amir Capua, See-Hun Yang, et al. "Separation of enantiomers by their enantiospecific interaction with achiral magnetic substrates." Science 360, no. 6395 (May 10, 2018): 1331–34. http://dx.doi.org/10.1126/science.aar4265.

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It is commonly assumed that recognition and discrimination of chirality, both in nature and in artificial systems, depend solely on spatial effects. However, recent studies have suggested that charge redistribution in chiral molecules manifests an enantiospecific preference in electron spin orientation. We therefore reasoned that the induced spin polarization may affect enantiorecognition through exchange interactions. Here we show experimentally that the interaction of chiral molecules with a perpendicularly magnetized substrate is enantiospecific. Thus, one enantiomer adsorbs preferentially when the magnetic dipole is pointing up, whereas the other adsorbs faster for the opposite alignment of the magnetization. The interaction is not controlled by the magnetic field per se, but rather by the electron spin orientations, and opens prospects for a distinct approach to enantiomeric separations.

21

Keswani, Neeti, and Pintu Das. "On the micromagnetic behavior of dipolar-coupled nanomagnets in defective square artificial spin ice systems." Journal of Applied Physics 126, no. 21 (December 7, 2019): 214304. http://dx.doi.org/10.1063/1.5127262.

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Beschi I S, Et al. "Applications of Deep Learning and Machine Learning in Healthcare Domain – A Literature Review." International Journal on Recent and Innovation Trends in Computing and Communication 11, no. 11 (November 30, 2023): 71–80. http://dx.doi.org/10.17762/ijritcc.v11i11.9107.

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In recent years, Artificial Intelligence (AI) has advanced rapidly in terms of software algorithms, hardware implementation, and implementations in a wide range of fields. The latest advances in AI applications in biomedicine, such as disease diagnostics, living assistance, biomedical information processing, and biomedical science, are summarised in this study. Brain-Computer Interfaces (BCIs), Arterial Spin Labeling (ASL) imaging, ASL-MRI, biomarkers, Natural Language Processing (NLP), and various algorithms all help to reduce errors and monitor disease progression. Computer-assisted diagnosis, decision support systems, expert systems, and software implementation can help doctors reduce intra- and inter-observer variability. In this paper, numerous researchers conduct a systematic literature review on the application and implementation of Machine Learning, Deep Learning, and Artificial Intelligence in the healthcare industry.

23

Tu, Huayao, Like Zhang, Yanxiang Luo, Wenxing Lv, Ting Lei, Jialin Cai, Bin Fang, et al. "Neural-like population coding based on spin-torque diode." Applied Physics Letters 122, no. 12 (March 20, 2023): 122402. http://dx.doi.org/10.1063/5.0142374.

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Neuroscience studies have shown that population coding in biological systems can carry out resilient information processing with ensemble of neurons. Such strategy is valuable for the future development of electronics, particularly as the downscaling of transistors is reaching atomic limits and causing problems of large device-to-device variability and even device failure. In this work, we propose that nanoscale spin-torque diode (STD) based on a magnetic tunnel junction can be used to implement population coding. We also demonstrate that a basis set obtained from a single STD by time multiplexing can realize the generation of cursive letters. Furthermore, different activation functions of an artificial neural network have been acquired. In addition, high recognition rates of the Mix National Institute of Standards and Technology handwritten digits up to 94.88% are achieved using an output function constructed from the experimental data. Our work may provide inspiration for designing neuromorphic computing systems.

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Aftab Ahmad Malik, Mujtaba Asad, and Waqar Azeem. "Artificial Intelligence A Byproduct of Natural Intelligence and Their Salient Features." Lahore Garrison University Research Journal of Computer Science and Information Technology 2, no. 3 (September 28, 2018): 1–6. http://dx.doi.org/10.54692/lgurjcsit.2018.020346.

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This paper mainly focuses on the creation of Artificial Intelligence (AI) using natural intelligence but the question to be considered whether the natural intelligence can be created using artificial intelligence or not. The Artificial intelligence is the outcome of functionality and capabilities of human brain called neural Network. In this paper, it is presumed that the artificial intelligence is a byproduct of natural intelligence and then we discuss some relationship between both of these, especially the working of natural intelligence. Some other important questions are raised to understand a deep linkage between natural and artificial intelligence. There exists lot of non-material phenomenon created by dint of natural intelligence (not created by human) causing to produce systems run by artificial intelligence theorems and algorithms working at backend. The software based on Knowledge Based Systems (KBS) derives its power from human wisdom and natural intelligence. There are several limitations on artificial intelligence. In creation of natural intelligence there is a great role of spirituality.Humans are creator of artificial intelligence with limited abilities. Actually AI started with invention of machines. The applications of creation of natural intelligence are vastly and abundantly known to humans of 21st Century, which are incorporated in the areas of Space Science, Anatomy, and motion ofPlants, spin of electron, Electronics, plant intelligence and Neural Science etc. The working of machines depending upon the artificial intelligence doesn't provide creativity or self-motivated innovations, within the meaning of natural intelligence.

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Kourtz, Peter. "Artificial intelligence: a new tool for forest management." Canadian Journal of Forest Research 20, no. 4 (April 1, 1990): 428–37. http://dx.doi.org/10.1139/x90-060.

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Articicial intelligence is a new science that deals with the representation, automatic acquisition, and use of knowledge. Artificial intelligence programs attempt to emulate human thought processes such as deduction, inference, language, and visual recognition. The goal of artificial intelligence is to make computers more useful for reasoning, planning, acting, and communicating with humans. Development of artificial intelligence applications involves the integration of advanced computer science, psychology, and sometimes robotics. Of the subfields that artificial intelligence can be broken into, the one of most immediate interest to forest management is expert systems. Expert systems involve encoding knowledge usually derived from an expert in a narrow subject area and using this knowledge to mimic his decision making. The knowledge is represented usually in the form of facts and rules, involving symbols such as English words. At the core of these systems is a mechanism that automatically searches for and pieces together the facts and rules necessary to solve a specific problem. Small expert systems can be developed on common microcomputers using existing low-cost commercial expert shells. Shells are general expert systems empty of knowledge. The user merely defines the solution structure and adds the desired knowledge. Larger systems usually require integration with existing forestry data bases and models. Their development requires either the relatively expensive expert system development tool kits or the use of one of the artificial intelligence development languages such as lisp or PROLOG. Large systems are expensive to develop, require a high degree of skill in knowledge engineering and computer science, and can require years of testing and modification before they become operational. Expert systems have a major role in all aspects of Canadian forestry. They can be used in conjunction with conventional process models to add currently lacking expert knowledge or as pure knowledge-based systems to solve problems never before tackled. They can preserve and accumulate forestry knowledge by encoding it. Expert systems allow us to package our forestry knowlege into a transportable and saleable product. They are a means to ensure consistent application of policies and operational procedures. There is a sense of urgency associated with the integration of artificial intelligence tools into Canadian forestry. Canada must awaken to the potential of this technology. Such systems are essential to improve industrial efficiency. A possible spin-off will be a resource knowledge business that can market our forestry knowledge worldwide. If we act decisively, we can easily compete with other countries such as Japan to fill this niche. A consortium of resource companies, provincial resource agencies, universities, and federal government laboratories is required to advance this goal.

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Giovannini, Loris, Barry W. Farmer, Justin S. Woods, Ali Frotanpour, Lance E. De Long, and Federico Montoncello. "Magnetic Normal Mode Calculations in Big Systems: A Highly Scalable Dynamical Matrix Approach Applied to a Fibonacci-Distorted Artificial Spin Ice." Magnetochemistry 7, no. 3 (March 8, 2021): 34. http://dx.doi.org/10.3390/magnetochemistry7030034.

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We present a new formulation of the dynamical matrix method for computing the magnetic normal modes of a large system, resulting in a highly scalable approach. The motion equation, which takes into account external field, dipolar and ferromagnetic exchange interactions, is rewritten in the form of a generalized eigenvalue problem without any additional approximation. For its numerical implementation several solvers have been explored, along with preconditioning methods. This reformulation was conceived to extend the study of magnetization dynamics to a broader class of finer-mesh systems, such as three-dimensional, irregular or defective structures, which in recent times raised the interest among researchers. To test its effectiveness, we applied the method to investigate the magnetization dynamics of a hexagonal artificial spin-ice as a function of a geometric distortion parameter following the Fibonacci sequence. We found several important features characterizing the low frequency spin modes as the geometric distortion is gradually increased.

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Galanis, Andreas, Daniel Štefankovič, and Eric Vigoda. "Inapproximability for Antiferromagnetic Spin Systems in the Tree Nonuniqueness Region." Journal of the ACM 62, no. 6 (December 10, 2015): 1–60. http://dx.doi.org/10.1145/2785964.

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Verhoeven, Jan W., and Michael N. Paddon-Row. "Photoinduced charge separation and recombination under distance, orientation, and spin controlled conditions." International Journal of Photoenergy 3, no. 2 (2001): 79–87. http://dx.doi.org/10.1155/s1110662x01000095.

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Great efforts have been made to mimic the efficient photoinduced charge separation and concomitant energy storage of natural photosynthetic systems via artificial (supra) molecular constructs as well as to design molecules with potential use for application in molecular electronic circuits. Close packing of such molecules introduces the problem of short-circuiting and cross talk between the separate molecular components. In the present paper the limits will be investigated to which such short-circuiting can be prevented by the use of saturated hydrocarbon (alkane) type insulating structures. Furthermore, as will be shown, several typically molecular scale operating principles such as orbital symmetry and spin multiplicity control can allow the realisation of systems in which fast and efficient charge separation is combined with very slow charge recombination even when the distance between the D(onor) and A(cceptor) moieties is very small.

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Chen, Jia-Ying, Xin-Gui Tang, Qiu-Xiang Liu, Yan-Ping Jiang, Wen-Min Zhong, and Fang Luo. "An Artificial Synapse Based on CsPbI3 Thin Film." Micromachines 13, no. 2 (February 10, 2022): 284. http://dx.doi.org/10.3390/mi13020284.

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With the data explosion in the intelligent era; the traditional von Neumann computing system is facing great challenges of storage and computing speed. Compared to the neural computing system, the traditional computing system has higher consumption and slower speed. However; the feature size of the chip is limited due to the end of Moore’s Law. An artificial synapse based on halide perovskite CsPbI3 was fabricated to address these problems. The CsPbI3 thin film was obtained by a one-step spin-coating method, and the artificial synapse with the structure of Au/CsPbI3/ITO exhibited learning and memory behavior similar to biological neurons. In addition, the synaptic plasticity was proven, including short-term synaptic plasticity (STSP) and long-term synaptic plasticity (LTSP). We also discuss the possibility of forming long-term memory in the device through changing input signals.

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Phillips, Winfred M. "The Artificial Heart: History and Current Status." Journal of Biomechanical Engineering 115, no. 4B (November 1, 1993): 555–57. http://dx.doi.org/10.1115/1.2895539.

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Twenty-years ago groups from California to Massachusetts were actively involved in the development of an artificial heart. From biomaterials development to biomedical power sources, the supporting industry and spin-off benefit was broad indeed. Young people were seeking careers in biomedical engineering and science. The National Institutes of Health was supporting artificial heart research at $10 to $12 million dollar levels. Groups at Andros, Inc. (now Baxter Novacor) and Stanford, Thoratec, Penn State and the Hershey Medical Center, Cleveland Clinic and the Division of Artificial Organs, the University of Utah, the Texas Heart Institute and the Baylor College of Medicine, Thermal Electron Corporation, and many more were the source of research and breakthrough development of pumps and systems for artificial hearts. We reported on performance criteria for an artificial heart pump at the First Biomechanics Symposium in 1973 [1]. By the beginning of the decade of the 90’s, thousands of presentations had been made and manuscripts written reporting significant progress in the development of artificial heart pumps and systems. The Heart, Lung and Blood Institute of the National Institutes of Health was supporting an artificial heart contract research and development program at a level of $6 million dollars in 1991 [2]. Broad basic research grant activity also continues. The National Institutes of Health’s artificial heart program received renewed support from the Institute of Medicine’s special review in 1991 [3]. In December of 1992, the 16th Annual Cardiovascular Science and Technology Conference attracted over 500 attendees. This annual conference has provided a continuing forum for an update on progress in artificial heart development.

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Oliveira, Lara B., Teonis S. Paiva, Hamilton A. Teixeira, and Clodoaldo I. L. de Araujo. "Magnetoresistive Evidence of Degeneracy in Nanomagnets Obtained by Electrodeposition Technique." Magnetism 4, no. 2 (April 7, 2024): 104–13. http://dx.doi.org/10.3390/magnetism4020008.

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Inspired in pyrochlore materials presenting residual entropy and featuring collective excitation behaving like emergent monopoles, geometrically frustrated arrays of nanomagnets, denominated artificial spin ices (ASIs), were proposed as an interesting platform to investigate such excitation at room temperature. However, in such artificial systems, emergent magnetic monopoles lack the same freedom present their natural counterpart, once energetic strings connecting opposite magnetic charges arise. In this work, we aim to experimentally investigate the proposed degeneracy obtained in connected square arrays of ASIs, a characteristic that allows a reduction in the string connecting monopole–antimonopole pairs in regular non-connected ASIs and could represent an important development for technological applications of connected nanomagnets. As in general those systems are developed by nanofabrication processes involving expensive and time-consuming physical vapour deposition techniques, we also present a new nanofabrication route using an electrodeposition technique for permalloy growth in different lattice geometries as an alternative for fast and low-cost ASI system production.

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Montoncello, F., M. T. Kaffash, H. Carfagno, M. F. Doty, G. Gubbiotti, and M. B. Jungfleisch. "A Brillouin light scattering study of the spin-wave magnetic field dependence in a magnetic hybrid system made of an artificial spin-ice structure and a film underlayer." Journal of Applied Physics 133, no. 8 (February 28, 2023): 083901. http://dx.doi.org/10.1063/5.0140866.

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We present a combined Brillouin light scattering (BLS) and micromagnetic simulation investigation of the magnetic-field-dependent spin-wave spectra in a hybrid structure made of permalloy (NiFe) artificial spin-ice (ASI) systems, composed of stadium-shaped nanoislands, deposited on the top of an unpatterned permalloy film with a nonmagnetic spacer layer. The thermal spin-wave spectra were recorded by BLS as a function of the magnetic field applied along the symmetry direction of the ASI sample. Magneto-optic Kerr effect magnetometry was used to measure the hysteresis loops in the same orientation as the BLS measurements. The frequency and the intensity of several spin-wave modes detected by BLS were measured as a function of the applied magnetic field. Micromagnetic simulations enabled us to identify the modes in terms of their frequency and spatial symmetry and to extract information about the existence and strength of the dynamic coupling, relevant only to a few modes of a given hybrid system. Using this approach, we suggest a way to understand if the dynamic coupling between ASI and film modes is present or not, with interesting implications for the development of future three-dimensional magnonic applications and devices.

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Orlowski-Feldhusen, Fabian, Sebastian Kottmeier, Ansgar Heidecker, Olaf Mierheim, Oliver Kolakowski, and Robert Klöpper. "The Eu:CROPIS Mass Property Campaign: Trimming a Spin-Stabilized Compact Satellite for a Long-Term Artificial Gravity Experiment." International Journal of Aerospace Engineering 2020 (November 1, 2020): 1–12. http://dx.doi.org/10.1155/2020/9193740.

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Eu:CROPIS (Euglena Combined Regenerative Organic Food Production in Space) is the first mission of DLR’s compact satellite program. The launch of Eu:CROPIS took place on December 3rd in 2018 on-board the Falcon 9 SSO-A mission. The satellite’s primary payload Eu:CROPIS features a biological experiment in the context of closed loop coupled life support systems. The Eu:CROPIS satellite mission uses spin stabilization along its Z -axis to provide defined acceleration levels for the primary and secondary payloads to simulate either a Moon or Mars gravity environment. For the payload performance, it is vital to achieve a minimum deviation between spacecraft Z -axis and the major moment of inertia (MoI) axis to minimize the offset of the envisaged acceleration levels. Specific moment of inertia ratios between the spin- and minor axes had to be maintained to allow the attitude control system to keep the satellite at a stable rotation despite environmental disturbances. This paper presents the adaptive and flexible trimming strategy applied during the flight model production, as well as the mass property measurement acceptance campaign and the respective results.

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Baum, K. G., G. Menezes, and M. Helguera. "Simulation of High-Resolution Magnetic Resonance Images on the IBM Blue Gene/L Supercomputer Using SIMRI." International Journal of Biomedical Imaging 2011 (2011): 1–8. http://dx.doi.org/10.1155/2011/305968.

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Medical imaging system simulators are tools that provide a means to evaluate system architecture and create artificial image sets that are appropriate for specific applications. We have modified SIMRI, a Bloch equation-based magnetic resonance image simulator, in order to successfully generate high-resolution 3D MR images of the Montreal brain phantom using Blue Gene/L systems. Results show that redistribution of the workload allows an anatomically accurate 2563voxel spin-echo simulation in less than 5 hours when executed on an 8192-node partition of a Blue Gene/L system.

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Sellies, Lisanne, Raffael Spachtholz, Sonja Bleher, Jakob Eckrich, Philipp Scheuerer, and Jascha Repp. "Single-molecule electron spin resonance by means of atomic force microscopy." Nature 624, no. 7990 (December 6, 2023): 64–68. http://dx.doi.org/10.1038/s41586-023-06754-6.

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AbstractUnderstanding and controlling decoherence in open quantum systems is of fundamental interest in science, whereas achieving long coherence times is critical for quantum information processing1. Although great progress was made for individual systems, and electron spin resonance (ESR) of single spins with nanoscale resolution has been demonstrated2–4, the understanding of decoherence in many complex solid-state quantum systems requires ultimately controlling the environment down to atomic scales, as potentially enabled by scanning probe microscopy with its atomic and molecular characterization and manipulation capabilities. Consequently, the recent implementation of ESR in scanning tunnelling microscopy5–8 represents a milestone towards this goal and was quickly followed by the demonstration of coherent oscillations9,10 and access to nuclear spins11 with real-space atomic resolution. Atomic manipulation even fuelled the ambition to realize the first artificial atomic-scale quantum devices12. However, the current-based sensing inherent to this method limits coherence times12,13. Here we demonstrate pump–probe ESR atomic force microscopy (AFM) detection of electron spin transitions between non-equilibrium triplet states of individual pentacene molecules. Spectra of these transitions exhibit sub-nanoelectronvolt spectral resolution, allowing local discrimination of molecules that only differ in their isotopic configuration. Furthermore, the electron spins can be coherently manipulated over tens of microseconds. We anticipate that single-molecule ESR-AFM can be combined with atomic manipulation and characterization and thereby paves the way to learn about the atomistic origins of decoherence in atomically well-defined quantum elements and for fundamental quantum-sensing experiments.

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León, Alejandro. "Thermal phase transition in artificial spin ice systems induces the formation and migration of monopole-like magnetic excitations." Physica B: Condensed Matter 500 (November 2016): 59–65. http://dx.doi.org/10.1016/j.physb.2016.07.012.

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Agliari, Elena, Alberto Fachechi, and Chiara Marullo. "Nonlinear PDEs approach to statistical mechanics of dense associative memories." Journal of Mathematical Physics 63, no. 10 (October 1, 2022): 103304. http://dx.doi.org/10.1063/5.0095411.

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Dense associative memories (DAMs) are widely used models in artificial intelligence for pattern recognition tasks; computationally, they have been proven to be robust against adversarial inputs and, theoretically, leveraging their analogy with spin-glass systems, they are usually treated by means of statistical-mechanics tools. Here, we develop analytical methods, based on nonlinear partial differential equations, to investigate their functioning. In particular, we prove differential identities involving DAM’s partition function and macroscopic observables useful for a qualitative and quantitative analysis of the system. These results allow for a deeper comprehension of the mechanisms underlying DAMs and provide interdisciplinary tools for their study.

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He, Cheng, Xiao-Chen Sun, Xiao-Ping Liu, Ming-Hui Lu, Yulin Chen, Liang Feng, and Yan-Feng Chen. "Photonic topological insulator with broken time-reversal symmetry." Proceedings of the National Academy of Sciences 113, no. 18 (April 18, 2016): 4924–28. http://dx.doi.org/10.1073/pnas.1525502113.

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A topological insulator is a material with an insulating interior but time-reversal symmetry-protected conducting edge states. Since its prediction and discovery almost a decade ago, such a symmetry-protected topological phase has been explored beyond electronic systems in the realm of photonics. Electrons are spin-1/2 particles, whereas photons are spin-1 particles. The distinct spin difference between these two kinds of particles means that their corresponding symmetry is fundamentally different. It is well understood that an electronic topological insulator is protected by the electron’s spin-1/2 (fermionic) time-reversal symmetry Tf2=−1. However, the same protection does not exist under normal circumstances for a photonic topological insulator, due to photon’s spin-1 (bosonic) time-reversal symmetry Tb2=1. In this work, we report a design of photonic topological insulator using the Tellegen magnetoelectric coupling as the photonic pseudospin orbit interaction for left and right circularly polarized helical spin states. The Tellegen magnetoelectric coupling breaks bosonic time-reversal symmetry but instead gives rise to a conserved artificial fermionic-like-pseudo time-reversal symmetry, Tp (Tp2=−1), due to the electromagnetic duality. Surprisingly, we find that, in this system, the helical edge states are, in fact, protected by this fermionic-like pseudo time-reversal symmetry Tp rather than by the bosonic time-reversal symmetry Tb. This remarkable finding is expected to pave a new path to understanding the symmetry protection mechanism for topological phases of other fundamental particles and to searching for novel implementations for topological insulators.

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Balasubramanian, Krishnan. "Symmetry, Combinatorics, Artificial Intelligence, Music and Spectroscopy." Symmetry 13, no. 10 (October 2, 2021): 1850. http://dx.doi.org/10.3390/sym13101850.

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Symmetry forms the foundation of combinatorial theories and algorithms of enumeration such as Möbius inversion, Euler totient functions, and the celebrated Pólya’s theory of enumeration under the symmetric group action. As machine learning and artificial intelligence techniques play increasingly important roles in the machine perception of music to image processing that are central to many disciplines, combinatorics, graph theory, and symmetry act as powerful bridges to the developments of algorithms for such varied applications. In this review, we bring together the confluence of music theory and spectroscopy as two primary disciplines to outline several interconnections of combinatorial and symmetry techniques in the development of algorithms for machine generation of musical patterns of the east and west and a variety of spectroscopic signatures of molecules. Combinatorial techniques in conjunction with group theory can be harnessed to generate the musical scales, intensity patterns in ESR spectra, multiple quantum NMR spectra, nuclear spin statistics of both fermions and bosons, colorings of hyperplanes of hypercubes, enumeration of chiral isomers, and vibrational modes of complex systems including supergiant fullerenes, as exemplified by our work on the golden fullerene C150,000. Combinatorial techniques are shown to yield algorithms for the enumeration and construction of musical chords and scales called ragas in music theory, as we exemplify by the machine construction of ragas and machine perception of musical patterns. We also outline the applications of Hadamard matrices and magic squares in the development of algorithms for the generation of balanced-pitch chords. Machine perception of musical, spectroscopic, and symmetry patterns are considered.

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León, A., and J. Pozo. "Using a genetic algorithm to study properties of minimum energy states and geometrical frustration in artificial “spin ice” systems." Journal of Magnetism and Magnetic Materials 320, no. 3-4 (February 2008): 210–16. http://dx.doi.org/10.1016/j.jmmm.2007.05.029.

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P. Soetanto, Danny. "APPLICATION OF FUZZY COGNITIVE MAPS ON POLICY ANALYSIS: DETERMINING THE POLICY OF SUPPORTING THE ACADEMIC SPIN OFFS." Jurnal Teknik Industri 4, no. 2 (July 9, 2004): 93–101. http://dx.doi.org/10.9744/jti.4.2.93-101.

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Fuzzy Cognitive Map (FCM) is a type of artificial neural network. It can be viewed as a weighted directed graph in which vertices represent concepts and edges represent causal links between them. An FCM can be used as an intelligent decision support system (DSS) tool. It works by representing important issues in a given situation and their causal relationships. The evolution of a dynamic system with time can be simulated and the behavior of the systems can be predicted and explained using an FCM. In this case FCM is used to ditermine the policy to support the academic spin off. Simulation brings forth some conclusions and the best policy can be chosen.

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HORVÁTH, DENIS, and MARTIN GMITRA. "THE SELF-ORGANIZED MULTI-LATTICE MONTE CARLO SIMULATION." International Journal of Modern Physics C 15, no. 09 (November 2004): 1249–68. http://dx.doi.org/10.1142/s0129183104006674.

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Self-organized Monte Carlo simulations of 2D Ising ferromagnet on the square lattice are performed. The essence of the suggested simulation method is an artificial dynamics consisting of the well-known single-spin-flip Metropolis algorithm supplemented by a random walk on the temperature axis. The walk is biased towards the critical region through a feedback based on instantaneous energy and magnetization cumulants, which are updated at every Monte Carlo step and filtered through a special recursion algorithm. The simulations revealed the invariance of the temperature probability distribution function, once some self-organized critical steady regime is reached, which is called here noncanonical equilibrium. The mean value of this distribution approximates the pseudocritical temperature of canonical equilibrium. In order to suppress finite-size effects, the self-organized approach is extended to multi-lattice systems, where the feedback basis on pairs of instantaneous estimates of the fourth-order magnetization cumulant on two systems of different size. These replica-based simulations resemble, in Monte Carlo lattice systems, some of the invariant statistical distributions of standard self-organized critical systems.

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Metz, Fernando L., and Thomas Peron. "Mean-field theory of vector spin models on networks with arbitrary degree distributions." Journal of Physics: Complexity 3, no. 1 (February 3, 2022): 015008. http://dx.doi.org/10.1088/2632-072x/ac4bed.

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Abstract Understanding the relationship between the heterogeneous structure of complex networks and cooperative phenomena occurring on them remains a key problem in network science. Mean-field theories of spin models on networks constitute a fundamental tool to tackle this problem and a cornerstone of statistical physics, with an impressive number of applications in condensed matter, biology, and computer science. In this work we derive the mean-field equations for the equilibrium behavior of vector spin models on high-connectivity random networks with an arbitrary degree distribution and with randomly weighted links. We demonstrate that the high-connectivity limit of spin models on networks is not universal in that it depends on the full degree distribution. Such nonuniversal behavior is akin to a remarkable mechanism that leads to the breakdown of the central limit theorem when applied to the distribution of effective local fields. Traditional mean-field theories on fully-connected models, such as the Curie–Weiss, the Kuramoto, and the Sherrington–Kirkpatrick model, are only valid if the network degree distribution is highly concentrated around its mean degree. We obtain a series of results that highlight the importance of degree fluctuations to the phase diagram of mean-field spin models by focusing on the Kuramoto model of synchronization and on the Sherrington–Kirkpatrick model of spin-glasses. Numerical simulations corroborate our theoretical findings and provide compelling evidence that the present mean-field theory describes an intermediate regime of connectivity, in which the average degree c scales as a power c ∝ N b (b < 1) of the total number N ≫ 1 of spins. Our findings put forward a novel class of spin models that incorporate the effects of degree fluctuations and, at the same time, are amenable to exact analytic solutions.

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Chen, Hao, So Young Jeon, and Sara A. Majetich. "Magnetostatic coupling effects on reversal dynamics." Journal of Physics D: Applied Physics 55, no. 26 (April 8, 2022): 265002. http://dx.doi.org/10.1088/1361-6463/ac62a1.

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Abstract The effects of magnetostatic coupling on switching dynamics are investigated for assemblies of patterned disc-shaped magnetic elements using mumax3 micromagnetic simulations. The arrangements of coupled dots were designed using information about the switching fields and reversal dynamics of isolated dots, as well as the magnitude of the magnetic stray fields they generate. The magnetization dynamics for individual dots was examined during a reversal cascade down a linear chain of dots. The magnetization angle fluctuated much more when neighboring dots have opposite magnetization directions, consistent with a lower energy barrier for reversal. The data were analyzed to differentiate thermal and interaction field effects. While many systems of interacting nanomagnets have been analyzed in terms of empirical models, the dynamical energy barrier approach offers a methodology with a more detailed and physically intuitive way to study both simple systems like the chain and more complex assemblies such as artificial spin ice.

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Kuleta, Patryk, Jonathan Lasham, Marcin Sarewicz, Iwona Ekiert, Vivek Sharma, Robert Ekiert, and Artur Osyczka. "Hydrogen bonding rearrangement by a mitochondrial disease mutation in cytochrome bc1 perturbs heme bH redox potential and spin state." Proceedings of the National Academy of Sciences 118, no. 33 (August 13, 2021): e2026169118. http://dx.doi.org/10.1073/pnas.2026169118.

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Hemes are common elements of biological redox cofactor chains involved in rapid electron transfer. While the redox properties of hemes and the stability of the spin state are recognized as key determinants of their function, understanding the molecular basis of control of these properties is challenging. Here, benefiting from the effects of one mitochondrial disease–related point mutation in cytochrome b, we identify a dual role of hydrogen bonding (H-bond) to the propionate group of heme bH of cytochrome bc1, a common component of energy-conserving systems. We found that replacing conserved glycine with serine in the vicinity of heme bH caused stabilization of this bond, which not only increased the redox potential of the heme but also induced structural and energetic changes in interactions between Fe ion and axial histidine ligands. The latter led to a reversible spin conversion of the oxidized Fe from 1/2 to 5/2, an effect that potentially reduces the electron transfer rate between the heme and its redox partners. We thus propose that H-bond to the propionate group and heme-protein packing contribute to the fine-tuning of the redox potential of heme and maintaining its proper spin state. A subtle balance is needed between these two contributions: While increasing the H-bond stability raises the heme potential, the extent of increase must be limited to maintain the low spin and diamagnetic form of heme. This principle might apply to other native heme proteins and can be exploited in engineering of artificial heme-containing protein maquettes.

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Wade, Nicholas J. "The Original Spin Doctors—The Meeting of Perception and Insanity." Perception 34, no. 3 (March 2005): 253–60. http://dx.doi.org/10.1068/p3403ed.

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Wang, Manman, Yuhai Yuan, and Yanfeng Jiang. "Realization of Artificial Neurons and Synapses Based on STDP Designed by an MTJ Device." Micromachines 14, no. 10 (September 23, 2023): 1820. http://dx.doi.org/10.3390/mi14101820.

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As the third-generation neural network, the spiking neural network (SNN) has become one of the most promising neuromorphic computing paradigms to mimic brain neural networks over the past decade. The SNN shows many advantages in performing classification and recognition tasks in the artificial intelligence field. In the SNN, the communication between the pre-synapse neuron (PRE) and the post-synapse neuron (POST) is conducted by the synapse. The corresponding synaptic weights are dependent on both the spiking patterns of the PRE and the POST, which are updated by spike-timing-dependent plasticity (STDP) rules. The emergence and growing maturity of spintronic devices present a new approach for constructing the SNN. In the paper, a novel SNN is proposed, in which both the synapse and the neuron are mimicked with the spin transfer torque magnetic tunnel junction (STT-MTJ) device. The synaptic weight is presented by the conductance of the MTJ device. The mapping of the probabilistic spiking nature of the neuron to the stochastic switching behavior of the MTJ with thermal noise is presented based on the stochastic Landau–Lifshitz–Gilbert (LLG) equation. In this way, a simplified SNN is mimicked with the MTJ device. The function of the mimicked SNN is verified by a handwritten digit recognition task based on the MINIST database.

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Mercaldo, Lucia V., Vladimir V. Talanov, Steven M. Anlage, Carmine Attanasio, and Luigi Maritato. "Microwave Electrodynamics of low TC and high TC Systems with Coexisting Superconductivity and Magnetism." International Journal of Modern Physics B 14, no. 25n27 (October 30, 2000): 2920–25. http://dx.doi.org/10.1142/s0217979200003101.

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We investigate the microwave electrodynamics of both artificial low T C superconducting/magnetic (S/M) layered structures and high T C cuprates. In particular we focus on Nb/CuMn (superconducting/spin-glass) bilayers, and on GbBa 2 Cu 3 O 7-δ (GBCO) thin films, which show coexistence of superconductivity and long range ordered antiferromagnetism below T N = 2.2 K . In both cases we are interested in the influence of magnetism on superconducivity. Moreover, in the GBCO case, we want to shed light on the problem of the determination of the pairing symmetry in the cuprates. First we show surface impedance data at 10 GHz on Nb/CuMn bilayers. We extract information about the induced order parameter in the magnetic layer and we compare it with the exotic behavior predicted for S/M proximity systems. Then we present microwave surface impedance data at three different frequencies on GBCO c-axis oriented epitaxial thin films. Both the resistance and the reactance data on GBCO show an unusual low temperature behavior, mainly due to change in magnetic permeability. This result indicates that the paramagnetism of the rare-earth ions has to be taken into account when extracting the superconducting penetration depth as a function of temperature, and thus determining the pairing state symmetry of the cuprates.

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Fiorentini, S., R. L. De Orio, J. Ender, S. Selberherr, M. Bendra, N. Jørstad, Wolfgang Goes, and V. Sverdlov. "Finite Element Method for MRAM Switching Simulations." WSEAS TRANSACTIONS ON SYSTEMS AND CONTROL 17 (December 31, 2022): 585–88. http://dx.doi.org/10.37394/23203.2022.17.64.

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The development of reliable simulation tools provides a valuable help in the design of modern MRAMdevices. Thanks to its versatility in the choice of meshes and discretization, the finite element method is a useful framework for the numerical solution of the magnetization dynamics. We review a finite element implementation of both the Landau-Lifshitz-Gilbert equation and the spin and charge drift-diffusion formalism in a solver employing open source software. The presented approach is successfully applied to emerging multilayered MRAM cells.

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Dobbins, Allan C., and Jon K. Grossmann. "Can Rotational Grouping Be Determined by the Initial Conditions?" i-Perception 9, no. 1 (January 2018): 204166951774833. http://dx.doi.org/10.1177/2041669517748338.

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Objects rotating in depth with an ambiguous rotation direction frequently appear to rotate together. Corotation is especially strong when the objects are interpretable as having a shared axis. We manipulated the initial conditions of the experiment by having pairs of objects initially appear to be unambiguous, and then make either a sudden or gradual transition to ambiguous spin. We find that in neither case do coaxial counter-rotating objects persist in being perceived as counter-rotating. This implies that the perceptual constraint that favors coaxial corotation overrides the initial perceptual state of the objects.

Journal articles on the topic 'Artificial spin systems'

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