检索结果-内蒙古大学图书馆

Double free-layer magnetic tunnel junctions for probabilistic bits

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Camsari, Kerem Y. Torunbalci, Mustafa Mert Borders, William A. Ohno, Hideo Fukami, Shunsuke Department of Electrical and Computer Engineering University of California Santa Barbara Santa BarbaraCA93106 United States Birck Nanotechnology Center Purdue University West LafayetteIN47907 United States Laboratory for Nanoelectronics and Spintronics Research Institute of Electrical Communication Tohoku University Japan Center for Spintronics Research Network Tohoku University Japan Center for Science and Innovation in Spintronics Tohoku University Japan WPI-Advanced Institute for Materials Research Tohoku University Japan

Naturally random devices that exploit ambient thermal noise have recently attracted attention as hardware primitives for accelerating probabilistic computing applications. One such approach is to use a low barrier nanomagnet as the free layer of a magnetic tunnel junction (MTJ) whose magnetic fluctuations are converted to resistance fluctuations in the presence of a stable fixed layer. Here, we propose and theoretically analyze a magnetic tunnel junction with no fixed layers but two free layers that are circularly shaped disk magnets. We use an experimentally benchmarked model that accounts for finite temperature magnetization dynamics, bias-dependent charge and spin-polarized currents as well as the dipolar coupling between the free layers. We obtain analytical results for statistical averages of fluctuations that are in good agreement with the numerical model. We find that the free layers with low diameters fluctuate to randomize the resistance of the MTJ in an approximately bias-independent manner. We show how such MTJs can be used to build a binary stochastic neuron (or a p-bit) in hardware. Unlike earlier stochastic MTJs that need to operate at a specific bias point to produce random fluctuations, the proposed design can be random for a wide range of bias values, independent of spin-transfer-torque pinning. Moreover, in the absence of a carefully optimized stabled fixed layer, the symmetric double-free layer stack can be manufactured using present day Magnetoresistive Random Access Memory (MRAM) technology by minimal changes to the fabrication process. Such devices can be used as hardware accelerators in energy-efficient computing schemes that require a large throughput of tunably random bits. Copyright © 2020, The Authors. All rights reserved.

关键词： MRAM devices

Directional detection of dark matter with diamond

学校读者我要写书评

暂无评论

arXiv 2020年

作者： Marshall, Mason C. Turner, Matthew J. Ku, Mark J.H. Phillips, David F. Walsworth, Ronald L. Department of Electrical and Computer Engineering University of Maryland College ParkMD20742 United States Center for Astrophysics Harvard & Smithsonian CambridgeMA02138 United States Department of Physics Harvard University CambridgeMA02138 United States Center for Brain Science Harvard University CambridgeMA02138 United States Department of Physics and Astronomy University of Delaware NewarkDE19716 United States Department of Materials Science and Engineering University of Delaware NewarkDE19716 United States Quantum Technology Center University of Maryland College ParkMD20742 United States Department of Physics University of Maryland College ParkMD20742 United States

Searches for WIMP dark matter will in the near future be sensitive to solar neutrinos. Directional detection offers a method to reject solar neutrinos and improve WIMP searches, but reaching that sensitivity with existing directional detectors poses challenges. We propose a combined atomic/particle physics approach using a large-volume diamond detector. WIMP candidate events trigger a particle detector, after which spectroscopy of nitrogen vacancy centers reads out the direction of the incoming particle. We discuss the current state of technologies required to realize directional detection in diamond and present a path towards a detector with sensitivity below the neutrino floor. Copyright © 2020, The Authors. All rights reserved.

关键词： Galaxies

2022 Roadmap on Neuromorphic Computing and engineering

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Christensen, Dennis Valbjørn Dittmann, Regina Linares-Barranco, Bernabé Sebastian, Abu Le Gallo, Manuel Redaelli, Andrea Slesazeck, Stefan Mikolajick, Thomas Spiga, Sabina Menzel, Stephan Valov, Ilia Milano, Gianluca Ricciardi, Carlo Liang, Shi-Jun Miao, Feng Lanza, Mario Quill, Tyler J. Keene, Scott T. Salleo, Alberto Grollier, Julie Marković, Danijela Mizrahi, Alice Yao, Peng Yang, J. Joshua Indiveri, Giacomo Strachan, John Paul Datta, Suman Vianello, Elisa Valentian, Alexandre Feldmann, Johannes Li, Xuan Pernice, Wolfram H.P. Bhaskaran, Harish Furber, Steve Neftci, Emre Scherr, Franz Maass, Wolfgang Ramaswamy, Srikanth Tapson, Jonathan Panda, Priyadarshini Kim, Youngeun Tanaka, Gouhei Thorpe, Simon Bartolozzi, Chiara Cleland, Thomas A. Posch, Christoph Liu, Shih-Chii Panuccio, Gabriella Mahmud, Mufti Mazumder, Arnab Neelim Hosseini, Morteza Mohsenin, Tinoosh Donati, Elisa Tolu, Silvia Galeazzi, Roberto Christensen, Martin Ejsing Holm, Sune Ielmini, Daniele Pryds, N. Department of Energy Conversion and Storage Technical University of Denmark Kgs. LyngbyDK-2800 Denmark Peter Gruenberg Institute 7 Forschungszentrum Juelich GmbH Juelich52425 Germany JARA-FIT RWTH Aachen University Aachen52056 Germany CSIC Universidad de Sevilla Seville41092 Spain IBM Research Zurich Switzerland STMicroelectronics Agrate Italy Dresden01187 Germany Institute of Semiconductors and Microsystems TU Dresden Dresden Germany CNR-IMM Unit of Agrate Brianza via C. Olivetti 2 MB Agrate Brianza Italy Juelich Germany Torino Italy Department of Applied Science and Technology Politecnico di Torino Torino Italy National Laboratory of Solid State Microstructures School of Physics Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing China Thuwal23955-6900 Saudi Arabia Department of Materials Science and Engineering Stanford University StanfordCA94305 United States Department of Engineering University of Cambridge CambridgeCB2 1PZ United Kingdom Unité Mixte de Physique CNRS Thales Université Paris-Saclay Palaiseau91767 France Electrical and Computer Engineering Department University of Southern California Los AngelesCA United States Institute of Neuroinformatics University of Zurich ETH Zurich Switzerland Hewlett Packard Laboratories Hewlett Packard Enterprise San JoseCA United States Department of Electrical Engineering University of Notre Dame Notre DameIN United States CEA LETI Université Grenoble Alpes Grenoble France CEA LIST Université Grenoble Alpes Grenoble France Department of Materials University of Oxford Parks Road OxfordOX1 3PH United Kingdom Institute of Physics University of Münster Heisenbergstr. 11 Heisenbergstr Münster48149 Germany Center for Soft Nanoscience University of Münster Münster48149 Germany The University of Manchester United Kingdom Department of Cognitive Sciences University of California Irvine IrvineCA United States Institute of Theoretica

Modern computation based on the von Neumann architecture is today a mature cutting-edge science. In the Von Neumann architecture, processing and memory units are implemented as separate blocks interchanging data intensively and continuously. This data transfer is responsible for a large part of the power consumption. The next generation computer technology is expected to solve problems at the exascale with 1018 calculations each second. Even though these future computers will be incredibly powerful, if they are based on von Neumann type architectures, they will consume between 20 and 30 megawatts of power and will not have intrinsic physically built-in capabilities to learn or deal with complex data as our brain does. These needs can be addressed by neuromorphic computing systems which are inspired by the biological concepts of the human brain. This new generation of computers has the potential to be used for the storage and processing of large amounts of digital information with much lower power consumption than conventional processors. Among their potential future applications, an important niche is moving the control from data centers to edge devices. The aim of this Roadmap is to present a snapshot of the present state of neuromorphic technology and provide an opinion on the challenges and opportunities that the future holds in the major areas of neuromorphic technology, namely materials, devices, neuromorphic circuits, neuromorphic algorithms, applications, and ethics. The Roadmap is a collection of perspectives where leading researchers in the neuromorphic community provide their own view about the current state and the future challenges for each research area. We hope that this Roadmap will be a useful resource by providing a concise yet comprehensive introduction to readers outside this field, for those who are just entering the field, as well as providing future perspectives for those who are well established in the neuromorphic computing community. © 2021,

关键词： Data transfer

Flatband-Induced Itinerant Ferromagnetism in RbCo2Se2

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Huang, Jianwei Wang, Zhicai Pang, Hongsheng Wu, Han Cao, Huibo Mo, Sung-Kwan Rustagi, Avinash Kemper, A.F. Wang, Meng Yi, Ming Birgeneau, R.J. Department of Physics and Astronomy Rice University HoustonTX77005 United States School of the Gifted Young University of Science and Technology of China Hefei Anhui230026 China Neutron Scattering Division Oak Ridge National Laboratory Oak RidgeTN37831 United States Advanced Light Source Lawrence Berkeley National Lab BerkeleyCA94720 United States Department of Physics North Carolina State University RaleighNC27695 United States School of Electrical and Computer Engineering Purdue University West LafayetteIN47907 United States School of Physics Sun Yat-Sen University Guangzhou Guangdong510275 China Department of Physics University of California BerkeleyCA94720 United States Materials Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States

ACo2Se2 (A=K,Rb,Cs) is a homologue of the iron-based superconductor, AFe2Se2. From a comprehensive study of RbCo2Se2 via measurements of magnetization, transport, neutron diffraction, angle-resolved photoemission spectroscopy, and first-principle calculations, we identify a ferromagnetic order accompanied by an orbital-dependent spin-splitting of the electronic dispersions. Furthermore, we identify the ordered moment to be dominated by a dx2−y2 flatband near the Fermi level, which exhibits the largest spin splitting across the ferromagnetic transition, suggesting an itinerant origin of the ferromagnetism. In the broader context of the iron-based superconductors, we find this dx2−y2 flatband to be a common feature in the band structures of both iron-chalcogenides and iron-pnictides, accessible via heavy electron doping. Copyright © 2021, The Authors. All rights reserved.

关键词： Selenium compounds

Telecommunication-wavelength lasing in er-doped gan multiple quantum wells at room temperature

学校读者我要写书评

暂无评论

Telecommunication-wavelength lasing in er-doped gan multiple...

Advanced Solid State Lasers, ASSL 2018

作者： Ho, V.X. Al Tahtamouni, T.M. Wang, Y. Jiang, H.X. Lin, J.Y. Zavada, J.M. Vinh, N.Q. Department of Physics Center for Soft Matter and Biological Physics Virginia Tech BlacksburgVA24061 United States Materials Science and Technology Program College of Arts and Sciences Qatar University Doha2713 Qatar Department of Electrical and Computer Engineering Texas Tech University LubbockTX79409 United States Department of Electrical and Computer Engineering New York University BrooklynNY11201 United States

We report the realization of room-temperature, stimulated-emission in Er-doped-GaN multiple-quantum-wells at the 1.5-µm. Structures were grown by MOCVD and lasing was confirmed by threshold-behaviors of emission-... 详细信息

ISBN: (纸本)9781943580484

关键词： Semiconductor quantum wells

Low-cost,μm-thick,tape-free electronic tattoo sensors with minimized motion and sweat artifacts

学校读者我要写书评

暂无评论

npj Flexible Electronics 2018年第1期2卷 35-41页

作者： Youhua Wang Yitao Qiu Shideh Kabiri Ameri Hongwoo Jang Zhaohe Dai YongAn Huang Nanshu Lu Center for Mechanics of Solids Structures and MaterialsDepartment of Aerospace Engineering and Engineering MechanicsThe University of Texas at AustinAustinTX 78712USA State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhanChina Flexible Electronics Research Center Huazhong University of Science and TechnologyWuhanChina Deparment of Electrical and Computer Engineering The University of Texas at AustinAustinTXUSA Texas Materials Institute The University of Texas at AustinAustinTXUSA Department of Biomedical Engineering The University of Texas at AustinAustinTXUSA Present address:Department of Civil&Environmental Engineering Stanford UniversityStanfordCA 94305USA

Electronic tattoos(e-tattoos),also known as epidermal electronics,are ultra-thin and ultra-soft noninvasive but skin-conformable devices with capabilities including physiological sensing and transdermal stimulation and *** fabrication of e-tattoos out of conventional inorganic electronic materials used to be tedious and *** developed cut-and-paste method has significantly simplified the process and lowered the ***,existing cut-and-paste method entails a medical tape on which the electronic tattoo sensors should be pasted,which increases tattoo thickness and degrades its *** address this problem,here we report a slightly modified cut-and-paste method to fabricate low-cost,open-mesh e-tattoos with a total thickness of just 1.5μm.E-tattoos of such thinness can be directly pasted on human skin and conforms to natural skin *** demonstrate that this ultra-thin,tape-free e-tattoo can confidently measure electrocardiogram(ECG),skin temperature,and skin *** rate and even respiratory rate can be extracted from the ECG signals.A special advantage of such ultra-thin e-tattoo is that it is capable of high-fidelity sensing with minimized motion artifacts under various body *** of perspiration are found to be insignificant due to the breathability of such e-tattoos.

关键词： paste cost electronic

Low-cost open-source voltage and current monitor for gas metal arc weld 3D printing

学校读者我要写书评

暂无评论

Rivista Italiana della Saldatura 2017年第1期69卷 73-84页

作者： Pinar, A. Wijnen, B. Anzalone, G.C. Hanvens, T.C. Sanders, P.G. Pearce, J.M. Michigan Technological University Department of Electrical and Computer Engineering HoughtonMI United States Michigan Technological University Department of Materials Science and Engineering HoughtonMI United States Michigan Technological University Department of Electrical and Computer Engineering Department of Computer Science HoughtonMI United States Michigan Technological University Department of Electrical and Computer Engineering Department of Materials Science and Engineering HoughtonMI United States

Arduino open-source microcontrollers are well known in sensor applications for scientific equipment and for controlling RepRap 3D printers. Recently low-cost open-source gas metal arc weld (GMAW) RepRap 3D printers have been developed. The entry-level welders used have minimal controls and therefore lack any real-time measurement of welder voltage or current. The preliminary work on process optimization of GMAW 3D printers requires a low-cost sensor and data logger system to measure welder current and voltage. This paper reports on the development of a low-cost open-source power measurement sensor system based on Arduino architecture. The sensor system was designed, built, and tested with two entry-level MIG welders. The full bill of materials and open source designs are provided. Voltage and current were measured while making stepwise adjustments to the manual voltage setting on the welder. Three conditions were tested while welding with steel and aluminum wire on steel substrates to assess the role of electrode material, shield gas, and welding velocity. The results showed that the open source sensor circuit performed as designed and could be constructed for Copyright © IIW 2016: all rights reserved.

关键词： 3D printers

Metal/BaTiO3/β-Ga2O3dielectric heterojunction diode with 5.7 MV/cm breakdown field

学校读者我要写书评

暂无评论

arXiv 2019年

作者： Xia, Zhanbo Chandrasekar, Hareesh Moore, Wyatt Wang, Caiyu Lee, Aidan McGlone, Joe Kalarickal, Nidhin Kurian Arehart, Aaron Ringel, Steven Yang, Fengyuan Rajan, Siddharth Electrical & Computer Engineering Ohio State University ColumbusOH43210 United States Materials Science and Engineering Ohio State University ColumbusOH43210 United States Department of Physics Ohio State University ColumbusOH43210 United States

Wide and ultra-wide band gap semiconductors can provide excellent performance due to their high energy band gap, which leads to breakdown electric fields that are more than an order of magnitude higher than conventional silicon electronics. In materials where p-type doping is not available, achieving this high breakdown field in a vertical diode or transistor is very challenging. We propose and demonstrate the use of dielectric heterojunctions that use extreme permittivity materials to achieve high breakdown field in a unipolar device. We demonstrate the integration of a high permittivity material BaTiO3with n-type β-Ga2O3to enable 5.7 MV/cm average electric field and 7 MV/cm peak electric field at the device edge, while maintaining forward conduction with relatively low on-resistance and voltage loss. The proposed dielectric heterojunction could enable new design strategies to achieve theoretical device performance limits in wide and ultrawide band gap semiconductors where bipolar doping is challenging. Copyright © 2019, The Authors. All rights reserved.

关键词： Dielectric materials

Boosting the Performance of MOEA/D-DRA with a Multi-Objective Hyper-Heuristic Based on Irace and UCB Method for Heuristic Selection

学校读者我要写书评

暂无评论

Boosting the Performance of MOEA/D-DRA with a Multi-Objectiv...

Congress on Evolutionary Computation

作者： Lucas Prestes Myriam R. Delgado Ricardo Lüders Richard Gonçalves Carolina P. Almeida Graduate Program in Electrical and Computer Engineering UTFPR Computer Science Department UNICENTRO

Multi-Objective Evolutionary Algorithm based on Decomposition with Dynamical Resource Allocation (MOEA/D-DRA) is one of the most successful decomposition based multiobjective algorithm. Its main feature is a mechanism to allocate different computational effort proportional to the difficult of each subproblem. Despite its success, MOEA/D-DRA has a large set of parameters and operators, whose selection could be a difficult task. This paper aims at improving the performance of MOEA/D-DRA by means of a hyper-heuristic using two parameter/operator selection phases: one off-line strongly based on Iterated Race Automatic Algorithm Configuration (Irace) and another one (online) based on the Upper Confidence Bound (UCB) technique. The proposed approach is compared with the original MOEA/D-DRA, NSGAII and IBEA over 51 instances of 7 well known benchmarks (CEC 2009, GLT, LZ09, MOP, DTLZ, ZDT and WFG). Results show that Irace and UCB are interesting methods to support the hyper-heuristic functioning when selecting parameters/operators of MOEA/D-DRA in the addressed problems.

关键词： Optimization Evolutionary computation Resource management Sociology Statistics Tuning Task analysis