检索结果-内蒙古大学图书馆

arXiv 2020年

作者： Zhang, Kangkang Wang, Cong Zhang, Minhao Bai, Zhanbin Xie, Fangfang Tan, Yuanzhi Guo, Yilv Hu, Kuo-Juei Cao, Lu Zhang, Shuai Tu, Xuecou Kang, Lin Chen, Jian Wu, Peiheng Wang, Xuefeng Wang, Jinlan Liu, Junming Wang, Baigeng Wang, Guanghou Xie, Suyuan Ji, Wei Shi, Su-Fei Reed, M.A. Song, Fengqi National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced Microstructures School of Physics Nanjing University Nanjing210093 China Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices Department of Physics Renmin University of China Beijing100872 China State Key Laboratory of Physical Chemistry of Solid Surfaces Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University Xiamen361005 China School of Physics Southeast University Nanjing211189 China School of Electronic Science and Engineering and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing210023 China Department of Chemical and Biological Engineering Rensselaer Polytechnic Institute TroyNY12180 United States Department of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute TroyNY12180 United States Departments of Applied Physics and Electrical Engineering Yale University New HavenCT06520 United States Nanjing211805 China

Single molecular electrets exhibiting single‐molecule electric polarization switching have been long desired as a platform for extremely small non-volatile storage devices, although it is controversial because of the poor stability of single molecular electric dipoles. Here we study the single molecular device of Gd@C82, where the encapsulated Gd atom forms a charge center, and we have observed a gate-controlled switching behavior between two sets of single-electron-transport stability diagrams. The switching is operated in a hysteresis loop with a coercive gate field of around 0.5 V/nm. Theoretical calculations have assigned the two conductance diagrams to corresponding energy levels of two states that the Gd atom is trapped at two different sites of the C82 cage, which possess two different permanent electrical dipole orientations. The two dipole states are stabilized by the anisotropic energy and separated by a transition energy barrier of 70 meV. Such switching is then accessed to the electric field driven reorientation of individual dipole while overcoming the barriers by the coercive gate field, and demonstrates the creation of a single molecular electret. Copyright © 2020, The Authors. All rights reserved.

关键词： Switching

来源：评论

学校读者我要写书评

暂无评论

Quantization of massive Dirac billiards and unification of nonrelativistic and relativistic chiral quantum scars

引用

Physical Review Research 2019年第3期1卷 033008-033008页

作者： Min-Yue Song Zi-Yuan Li Hong-Ya Xu Liang Huang Ying-Cheng Lai School of Physical Science and Technology and Key Laboratory for Magnetism and Magnetic Materials of MOE Lanzhou University Lanzhou Gansu 730000 China School of Electrical Computer and Energy Engineering Arizona State University Tempe Arizona 85287 USA Department of Physics Arizona State University Tempe Arizona 85287 USA

Quantum scars constitute one of the fundamental pillars in the traditional field of nonrelativistic quantum chaos. In relativistic quantum systems, chiral scars have been discovered recently whose wave functions concentrate on odd periodic orbits and break the time-reversal symmetry. We develop a theoretical framework to unify the scarring phenomena in nonrelativistic and relativistic quantum systems, which were previously thought to be distinct. In particular, we exploit massive Dirac billiard systems and derive semiclassical quantization rules to bridge the two opposite limits: the massless Dirac case and the large mass regime where the system effectively degenerates into one governed by the Schrödinger equation. A nontrivial phase is uncovered, which depends on the mass, the wave number, and the angle of reflection, and we demonstrate that this phase plays a key role in transforming the chiral scars and in bridging the relativistic and nonrelativistic quantum scars. In the large-mass limit, time-reversal symmetry is restored, as evidenced by a spectral analysis.

关键词： Quantum chaos Quantum scars

来源：评论

学校读者我要写书评

暂无评论

[email protected] core-shell nanoparticles as a p-type gas sensor: Novel synthesis, characterization, and their gas sensing properties with sensing mechanism

引用

Sensors and Actuators B: Chemical 2018年 268卷 223-231页

作者： Sanjit Manohar Majhi Gautam Kumar Naik Hu-Jun Lee Ho-Geun Song Cheul-Ro Lee In-Hwan Lee Yeon-Tae Yu Division of Advanced Materials Engineering and Research Center for Advanced Materials Development College of Engineering Chonbuk National University Jeonju 561-756 South Korea Electrical Engineering Program Computer Electrical and Mathematical Science and Engineering Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia Ogam Technology Jeonju 54882 South Korea Department of Materials Science and Engineering Korea University Seoul 02841 South Korea

In this work, [email protected] core-shell nanoparticles (C-S NPs) as a p-type gas sensing material was synthesized by a facile wet-chemical method, and evaluated their gas sensing properties as compared to the pristine NiO NPs gas sensors. Transmission electron microscope (TEM) results exhibited the well-dispersed formation of [email protected] C-S NPs having the total size of 70–120 nm and NiO shells having 30–50 nm thickness. The C-S morphology as well as the overall particle sizes are unchanged even at 500 °C. The gas sensing result reveals that the response of [email protected] C-S NPs gas sensor is higher than pristine NiO NPs gas sensor for 100 ppm of ethanol at 200 °C operating temperature. The baseline resistance in the air for [email protected] C-S NPs sensor is lowered as compared to pristine NiO NPs, which is due to the increased number of holes as charge carriers in [email protected] C-S NPs. The high response of [email protected] core-shell NPs as compared to pristine NiO NPs is attributed to electronic and chemical sensitization effects of Au. In [email protected] C-S structure, the contact between metal (Au) and semiconductor (NiO) formed a Schottky junction since Au metal acted as electron acceptor, a withdrawal of electrons from NiO by Au metal core leaved behind number of holes as charge carriers in [email protected] C-S NPs. Therefore, the baseline resistance of [email protected] C-S NPs greatly decreased than pristine NiO NPs, as a result the [email protected] C-S NPs showed higher response. On the other hand, in chemical sensitization effect, Au NPs catalyzed to dissociate O 2 molecules into ionic species. This work will give some clue to the researchers for the further development of p-type based C-S NPs sensors.

关键词： [email protected] Core-shell NPs Baseline resistance Sensitivity [email protected]

来源：评论

学校读者我要写书评

暂无评论

Exploration of intercell wireless millimeter-wave communication in the landscape of intelligent metasurfaces

arXiv

引用

arXiv 2019年

作者： Tasolamprou, Anna C. Pitilakis, Alexandros Abadal, Sergi Tsilipakos, Odysseas Timoneda, Xavier Taghvaee, Hamidreza Mirmoosa, Mohammad Sajjad Liu, Fu Liaskos, Christos Tsioliaridou, Ageliki Kantartzis, Nikolaos V. Manessis, Dionysios Georgiou, Julius Cabellos-Aparicio, Albert Alarcón, Eduard Pitsillides, Andreas Akyildiz, Ian Tretyakov, Sergei A. Economou, Eleftherios N. Kafesaki, Maria Soukoulis, Costas M. Foundation for Research and Technology Hellas Heraklion Crete71110 Greece Electrical and Computer Engineering Aristotle University of Thessaloniki Department Thessaloniki54124 Greece Universitat Politècnica de Catalunya Barcelona Spain Department of Electronics and Nanoengineering Aalto University P.O. Box 15500 AaltoFI-00076 Finland System Integration and Interconnection Technologies Fraunhofer IZM Berlin Germany Department of Electrical and Computer Engineering University of Cyprus Cyprus Department of Computer Science University of Cyprus Cyprus Georgia Institute of Technology School of Electrical and Computer Engineering United States Department of Physics University of Crete Heraklion Crete70013 Greece Department of Materials Science and Technology University of Crete Heraklion Crete70013 Greece Ames Laboratory Department of Physics and Astronomy Iowa State University AmesIA50011 United States

Software-defined metasurfaces are electromagnetically ultra-thin, artificial components that can provide engineered and externally controllable functionalities. The control over these functionalities is enabled by the metasurface tunability, which is implemented by embedded electronic circuits that modify locally the surface resistance and reactance. Integrating controllers within the metasurface cells, able to intercommunicate and adaptively reconfigure it, thus imparting a desired electromagnetic operation, opens the path towards the creation of an artificially intelligent (AI) fabric where each unit cell can have its own sensing, programmable computing, and actuation facilities. In this work we take a crucial step towards bringing the AI metasurface technology to emerging applications, in particular exploring the wireless mm-wave intercell communication capabilities in a software-defined HyperSurface designed for operation is the microwave regime. We examine three different wireless communication channels within the landscape of the reflective metasurface: Firstly, in the layer where the control electronics of the HyperSurface lie, secondly inside a dedicated layer enclosed between two metallic plates, and, thirdly, inside the metasurface itself. For each case we examine the physical implementation of the mm-wave transponder nodes, we quantify communication channel metrics, and we identify complexity vs. performance trade-offs. Copyright © 2019, The Authors. All rights reserved.

关键词： Millimeter waves

来源：评论

学校读者我要写书评

暂无评论

Experimental observation of high intrinsic thermal conductivity of AlN

arXiv

引用

arXiv 2019年

作者： Cheng, Zhe Koh, Yee Rui Mamun, Abdullah Shi, Jingjing Bai, Tingyu Huynh, Kenny Yates, Luke Liu, Zeyu Li, Ruiyang Lee, Eungkyu Liao, Michael Wang, Yekan Yu, Hsuan Ming Kushimoto, Maki Luo, Tengfei Goorsky, Mark S. Hopkins, Patrick E. Amano, Hiroshi Khan, Asif Graham, Samuel George W. Woodruff School of Mechanical Engineering Georgia Institute of Technology AtlantaGA30332 United States Department of Mechanical and Aerospace Engineering University of Virginia CharlottesvilleVA22904 United States Department of Electrical Engineering University of South Carolina ColumbiaSC29208 United States Materials Science and Engineering University of California Los Angeles Los AngelesCA91355 United States Department of Aerospace and Mechanical Engineering University of Notre Dame Notre DameIN46556 United States Department of Electrical Engineering and Computer Science Nagoya University Furo-cho Chikusa-ku Nagoya464-8603 Japan Institute of Materials and Systems for Sustainability Nagoya University Furo-cho Chikusa-ku Nagoya464-8601 Japan Department of Materials Science and Engineering University of Virginia CharlottesvilleVA22904 United States Department of Physics University of Virginia CharlottesvilleVA22904 United States School of Materials Science and Engineering Georgia Institute of Technology AtlantaGA30332 United States

AlN is an ultra-wide bandgap semiconductor which has been developed for applications including power electronics and optoelectronics. Thermal management of these applications is the key for stable device performance and allowing for long lifetimes. AlN, with its potentially high thermal conductivity, can play an important role serving as a dielectric layer, growth substrate, and heat spreader to improve device performance. However, the intrinsic high thermal conductivity of bulk AlN predicted by theoretical calculations has not been experimentally observed because of the difficulty in producing materials with low vacancy and impurity levels, and other associated defect complexes in AlN which can decrease the thermal conductivity. This work reports the growth of thick (>15 μm) AlN layers by metal-organic chemical vapor deposition with an air-pocketed AlN layer and the first experimental observation of intrinsic thermal conductivity from 130 K to 480 K that matches density-function-theory calculations for single crystal AlN, producing some of the highest values ever measured. Detailed material characterizations confirm the high quality of these AlN samples with one or two orders of magnitude lower impurity concentrations than seen in commercially available bulk AlN. Measurements of these commercially available bulk AlN substrates from 80 K to 480 K demonstrated a lower thermal conductivity, as expected. A theoretical thermal model is built to interpret the measured temperature dependent thermal conductivity. Our work demonstrates that it is possible to obtain theoretically high values of thermal conductivity in AlN and such films may impact the thermal management and reliability of future electronic and optoelectronics devices. Copyright © 2019, The Authors. All rights reserved.

关键词： Aluminum nitride

来源：评论

学校读者我要写书评

暂无评论

Suppressing phase disproportionation in quasi-2D perovskite light-emitting diodes

引用

Nature communications 2023年第1期14卷 397页

作者： Kang Wang Zih-Yu Lin Zihan Zhang Linrui Jin Ke Ma Aidan H Coffey Harindi R Atapattu Yao Gao Jee Yung Park Zitang Wei Blake P Finkenauer Chenhui Zhu Xiangeng Meng Sarah N Chowdhury Zhaoyang Chen Tanguy Terlier Thi-Hoai Do Yan Yao Kenneth R Graham Alexandra Boltasseva Tzung-Fang Guo Libai Huang Hanwei Gao Brett M Savoie Letian Dou Davidson School of Chemical Engineering Purdue University West Lafayette IN USA. Department of Physics Florida State University Tallahassee FL USA. Department of Chemistry Purdue University West Lafayette IN USA. Department of Chemistry University of Kentucky Lexington KY USA. Advanced Light Source Lawrence Berkeley National Laboratory Berkeley CA USA. School of Materials Science and Engineering Qilu University of Technology (Shandong Academy of Sciences) Jinan China. Birck Nanotechnology Center Purdue University West Lafayette IN USA. Department of Electrical and Computer Engineering and Texas Center for Superconductivity at the University of Houston (TcSUH) University of Houston Houston TX USA. SIMS laboratory Shared Equipment Authority Rice University Houston TX USA. Department of Photonics National Cheng Kung University Tainan Taiwan. Davidson School of Chemical Engineering Purdue University West Lafayette IN USA. dou10@purdue.edu. Birck Nanotechnology Center Purdue University West Lafayette IN USA. dou10@purdue.edu.

Electroluminescence efficiencies and stabilities of quasi-two-dimensional halide perovskites are restricted by the formation of multiple-quantum-well structures with broad and uncontrollable phase distributions. Here, we report a ligand design strategy to substantially suppress diffusion-limited phase disproportionation, thereby enabling better phase control. We demonstrate that extending the π-conjugation length and increasing the cross-sectional area of the ligand enables perovskite thin films with dramatically suppressed ion transport, narrowed phase distributions, reduced defect densities, and enhanced radiative recombination efficiencies. Consequently, we achieved efficient and stable deep-red light-emitting diodes with a peak external quantum efficiency of 26.3% (average 22.9% among 70 devices and cross-checked) and a half-life of ~220 and 2.8 h under a constant current density of 0.1 and 12 mA/cm, respectively. Our devices also exhibit wide wavelength tunability and improved spectral and phase stability compared with existing perovskite light-emitting diodes. These discoveries provide critical insights into the molecular design and crystallization kinetics of low-dimensional perovskite semiconductors for light-emitting devices.

关键词：

来源：评论

学校读者我要写书评

暂无评论

100pT/cm sensitive MEMS resonant magnetometer from a commercial accelerometer

arXiv

引用

arXiv 2019年

作者： Javor, Josh Stange, Alexander Pollock, Corey Fuhr, Nicholas Bishop, David J. Department of Mechanical Engineering Boston University BostonMA02215 United States Division of Materials Science and Engineering Boston University BostonMA02215 United States Department of Electrical and Computer Engineering Boston University BostonMA02215 United States Department of Physics Boston University BostonMA02215 United States Department of Biomedical Engineering Boston University BostonMA02215 United States

Magnetic sensing is present in our everyday interactions with consumer electronics, and also demonstrates potential for measurement of extremely weak biomagnetic fields, such as those of the heart and brain. In this work, we leverage the many benefits of the micro-electromechanical systems (MEMS) devices to fabricate a small, low power, inexpensive sensor whose resolution is in the range of weak biomagnetic fields. The sensor works at room temperature, and is suitable for consumer electronics integration. At present, such biomagnetic fields can only be measured by expensive mechanisms such as optical pumping and superconducting quantum interference devices (SQUIDs). Thus, our sensor suggests the opening of a large phase space for medical and consumer applications. The prototype fabrication is achieved by assembling micro-objects, including a permanent micromagnet, onto a post-release commercial MEMS accelerometer. With this system, we demonstrate a room temperature MEMS magnetometer, whose design is only sensitive to gradient magnetic fields and is generally insensitive to the Earth’s uniform field. In air, the sensor’s response is linear with a resolution of 1.1 nT cm-1 and spans over 3 decades of dynamic range to 4.6 µT cm-1. In 1 mTorr vacuum with 20 dB magnetic shielding, the sensor achieved 100 pT cm-1 resolution at resonance. The theoretical floor of this design is 110 fT cm-1 Hz-1/2 with a resolution of 13 fT cm-1, thus these devices hold promise for both magnetocardiography (MCG) and magnetoencephalography (MEG) applications. Copyright © 2019, The Authors. All rights reserved.

关键词： Magnetometers

来源：评论

学校读者我要写书评

暂无评论

Asymmetric Metal-dielectric Meta-cylinders and their Potential Applications from engineering Scattering Patterns to Spatial Optical Signal Processing

arXiv

引用

arXiv 2019年

作者： Momeni, Ali Safari, Mahdi Abdolali, Ali Kherani, Nazir P. Fleury, Romain Applied Electromagnetic Laboratory School of Electrical Engineering Iran University of Science and Technology Narmak Tehran Iran Department of Electrical and Computer Engineering University of Toronto 10 Kings College Road TorontoM5S 3G4 Canada Department of Materials Science and Engineering University of Toronto 140 College Street TorontoONM5S 3E4 Canada LausanneCH-1015 Switzerland

We propose a novel type of bi-anisotropic hybrid metal-dielectric structure comprising dielectric and metallic cylindrical wedges wherein the composite meta-cylinder enables advanced control of electric, magnetic and magnetoelectric resonances. We establish a theoretical framework in which the electromagnetic response of this meta-atom is described through the electric and magneticmultipole moments. The complete dynamic polarizability tensor, expressed in a compact form, is derived as a function of the Mie scattering coefficients. Flexibility in the design makes the proposed meta-cylinder a viable candidate for various applications in the microscopic (single meta-atom) and macroscopic (metasurface) levels. We show that the highly versatile bi-anisotropic meta-atom is amenable to being designed for the desired electromagnetic response, such as electric dipole-free and zero/near-zero (backward and forward) scattering at the microscopic level. In addition, we show that the azimuthal asymmetry gives rise to normal polarizability components which are vital elements in synthesizing asymmetric Optical Transfer Function (OTF) at the macroscopic *** conduct a precise inspection, from the microscopic to the macroscopic level, of the metasurface synthesis for emphasizing on the role of normal polarizability components for spatial optical signal processing. It is shown that this simple two-dimensional asymmetric meta-atom can perform first-order differentiation and edge detection at normal *** results reported herein contribute toward improving the physical understanding of wave interaction with artificial materials composed of asymmetric elongated metal-dielectric inclusions and open the potential of its application in spatial signal and image processing. Copyright © 2019, The Authors. All rights reserved.

关键词： Polarization

来源：评论

学校读者我要写书评

暂无评论

Corrigendum to ‘Successes and challenges of factor analysis/target transformation application to visible-to-near-infrared hyperspectral data’: [Icarus 365 (2021) 114402]

引用

Icarus 2021年 368卷

作者： J.D. Tarnas J.F. Mustard X. Wu E. Das K.M. Cannon C.B. Hundal A.C. Pascuzzo J.R. Kellner M. Parente Department of Earth Environmental and Planetary Sciences Brown University United States National Space Science Center Chinese Academy of Sciences China Department of Geology and Geological Engineering Colorado School of Mines United States Space Resources Program Colorado School of Mines United States Institute at Brown for Environment and Society Brown University United States Department of Ecology and Evolutionary Biology Brown University United States Department of Electrical and Computer Engineering University of Massachusetts at Amherst United States

来源：评论

学校读者我要写书评

暂无评论

Covert sensing using floodlight illumination

引用

Physical Review A 2019年第6期99卷 062321-062321页

作者： Christos N. Gagatsos Boulat A. Bash Animesh Datta Zheshen Zhang Saikat Guha College of Optical Sciences University of Arizona 1630 East University Boulevard Tucson Arizona 85719 USA Department of Electrical and Computer Engineering University of Arizona 1230 East Speedway Boulevard Tucson Arizona 85719 USA Department of Physics University of Warwick Coventry CV4 7AL United Kingdom Department of Materials Science and Engineering University of Arizona 1235 James E. Rogers Way Tucson Arizona 85721 USA

We propose a scheme for covert active sensing using floodlight illumination from a terahertz-bandwidth amplified spontaneous emission (ASE) source and heterodyne detection. We evaluate the quantum-estimation-theoretic performance limit of covert sensing, wherein a transmitter's attempt to sense a target phase is kept undetectable to a quantum-equipped passive adversary, by hiding the signal photons under the thermal noise floor. Despite the quantum state of each mode of the ASE source being mixed (thermal), and hence inferior compared to the pure coherent state of a laser mode, the thousand-times-higher optical bandwidth of the ASE source results in achieving a substantially superior performance compared to a narrow-band laser source by allowing the probe light to be spread over many more orthogonal temporal modes within a given integration time. Even though our analysis is restricted to single-mode phase sensing, this system could be applicable or extendible for various practical optical sensing applications.

关键词： Imaging & optical processing Metrology Quantum channels Quantum metrology Quantum optics Quantum sensing

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：