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Tunable artificial plasmonic nanolaser with wide spectrum emission operating at room temperature

Chinese Physics B 2024年第5期33卷 466-471页

作者：周鹏郭佳琦梁琨金磊梁熊玉李俊强邓绪彦秦建宇张家森于丽 State Key Laboratory of Information photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory for Artificial Microstructures and Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100876China peking university Yangtze Delta Institute of Optoelectronics Peking UniversityNantong 226010China

With the rapid development of information and communication technology,a key objective in the field of optoelectronic integrated devices is to reduce the nano-laser size and energy *** nanolasers are unable to exceed the diffraction limit and typically exhibit low modulation rates of several *** contrast,plasmonic nanolaser utilizes highly confined surface plasmon polariton(SPP)mode that can exceed diffraction limit and their strong Purcell effect can accelerate the modulation rates to several ***,we propose a parametrically tunable artificial plasmonic nanolasers based on metal–insulator–semiconductor–insulator–metal(MISIM)structure,which demonstrates its ability to compress the mode field volume toλ/*** the pump power increases,the proposed artificial plasmonic nanolaser exhibits 20-nm-wide output ***,we investigate the effects of various cavity parameters on the nanolaser’s output threshold,offering potentials for realizing low-threshold artificial plasmonic ***,we observe a blue shift in the center wavelength of the nanolaser output with thinner gain layer thickness,predominantly attributed to the increased exciton–photon coupling *** work brings inspiration to several areas,including spaser-based interconnects,nano-LEDs,spontaneous emission control,miniaturization of photon condensates,eigenmode engineering of plasmonic nanolasers,and optimal design driven by artificial intelligence(AI).

关键词： surface plasmon polaritons nanolaser ultrafast MISIM

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An isolated symmetrical 2T2R cell enabling high precision and high density for RRAM-based in-memory computing

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Science China(Information Sciences) 2024年第5期67卷 287-294页

作者： Yaotian LING Zongwei WANG Yuhang YANG Lin BAO Shengyu BAO Qishen WANG Yimao CAI Ru HUANG School of Integrated Circuits Beijing Advanced Innovation Center for Integrated Circuits Peking University State Key Laboratory of Information photonics and Optical Communications Beijing University of Posts and Telecommunications

In-memory computing(IMC), leveraging emerging memories, holds significant promise in overcoming memory limitations and improving energy efficiency. However, the prevailing IMC array structure based on serially connected transistors and memory cells(1T1R/2T2R), along with the signed weight mapping scheme, can lead to asymmetrical weight sensing issues(AWS) due to electrical asymmetry within the1T1R/2T2R structure, particularly in highly scaled cells where the transistor's resistance becomes significant. In this paper, we propose and fabricate an electrically symmetric memory cell based on a physically isolated 2T2R structure for IMC. This design aims to enhance the precision and density of RRAM-based IMC arrays. The 2T2R cells are manufactured using the back-end-of-line(BEOL) process of a commercial40 nm technology platform. The feasibility of this design is verified through measured and simulated results,showcasing its capability to address the issue of AWS. Compared to conventional 2T2R cells, this design achieves a considerably smaller transistor footprint without compromising accuracy, while also improving integration density by 42.2%. These innovative memory cell advancements have the potential to further advance high-energy-efficient IMC technology.

关键词： RRAM 2T2R multi-level storage weight asymmetry in-memory computing

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Investigation and mitigation of Mott neuronal oscillation fluctuation in spiking neural network

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Science China(Information Sciences) 2024年第2期67卷 291-301页

作者： Lindong WU Zongwei WANG Lin BAO Linbo SHAN Zhizhen YU Yunfan YANG Shuangjie ZHANG Guandong BAI Cuimei WANG John ROBERTSON Yuan WANG Yimao CAI Ru HUANG School of Integrated Circuits Peking University Beijing Advanced Innovation Center for Integrated Circuits State Key Laboratory of Information photonics and Optical Communications Beijing University of Posts and Telecommunications Department of Engineering University of Cambridge

Mott devices, featuring low hardware cost and high energy efficiency, have been demonstrated as a key oscillatory element in artificial neurons to enable spiking neural networks(SNNs) such as conversionbased SNNs(CSNNs). However, there will be inevitably non-ideal fluctuation in the oscillation behavior,causing the accuracy degradation of networks. In this paper, we investigate the Mott neuronal oscillation fluctuation(NOF) through experiments and modeling. The results show that the NOF phenomenon conforms to Gaussian distribution and originates from thermal fluctuation induced switching voltage variations. We construct a two-layer CSNN for image recognition tasks to study the NOF effect and propose the activation function boundary(AFB) method to strengthen the stability of the network. The results indicate that AFB can improve the accuracy of CSNN by up to 15.5% by tightening output distribution.

关键词： Mott neuron oscillation fluctuation variation-aware Mott neuronal model conversion-based spiking neural network activation function boundary

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Trace inequalities, isocapacitary inequalities, and regularity of the complex Hessian equations

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Science China Mathematics 2024年第3期67卷 557-576页

作者： Jiaxiang Wang Bin Zhou Beijing International Center for Mathematical research Peking UniversityBeijing 100871China School of Mathematical Sciences Peking UniversityBeijing 100871China

In this paper, we study the relations between trace inequalities(Sobolev and Moser-Trudinger types), isocapacitary inequalities, and the regularity of the complex Hessian and Monge-Amp`ere equations with respect to a general nonnegative Borel measure. We obtain a quantitative characterization for these relations through the properties of the capacity-minimizing functions.

关键词： complex Monge-Ampère equations plurisubharmonic functions Sobolev inequality Moser-Trudinger inequality

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Targeting LTA4H facilitates the reshaping of the immune microenvironment mediated by CCL5 and sensitizes ovarian cancer to Cisplatin

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Science China(Life Sciences) 2024年第6期67卷 1226-1241页

作者： Zhengyang Guo Jiaqi Huang Xiao Huo Chen Huang Xiaotong Yu Yan Sun Yanfang Li Tianhui He Hongyan Guo Jianling Yang Lixiang Xue Cancer Center of peking university Third Hospital Beijing 100191China Center of Basic Medical research Institute of Medical Innovation and ResearchPeking University Third HospitalBeijing 100191China peking university Third Hospital Cancer Center Department of Radiation OncologyPeking University Third HospitalBeijing 100191China Department of Obstetrics and Gynecology Peking University Third HospitalBeijing 100191China

Ovarian cancer is the most lethal and aggressive gynecological cancer with a high recurrence rate and is often diagnosed *** ovarian cancer,multiple metabolic enzymes of lipid metabolism are abnormally expressed,resulting in metabolism *** a characteristic pathway in polyunsaturated fatty acid(PUFA)metabolism,arachidonic acid(AA)metabolism is disturbed in ovarian ***,we established a 10-gene signature model to evaluate the prognostic risk of PUFA-related *** 10-gene signature has strong robustness and can play a stable predictive role in datasets of various platforms(TCGA,ICGC,and GSE17260).The high association between the risk subgroups and clinical characteristics indicated a good performance of the *** data further indicated that the high expression of LTA4H was positively correlated with poor prognosis in ovarian *** of LTA4H enhanced sensitivity to Cisplatin and modified the characteristics of immune cell infiltration in ovarian ***,our results indicate that CCL5 was involved in the aberrant metabolism of the AA/LTA4H axis,which contributes to the reduction of tumor-infiltrating CD8+T cells and immune escape in ovarian *** findings provide new insights into the prognosis and potential target of LTA4H/CCL5 in treating ovarian cancer.

关键词： ovarian cancer polyunsaturated fatty acids prognostic risk model LTA4H tumor immunity CCL5

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EPR-Net: constructing a non-equilibrium potential landscape via a variational force projection formulation

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National Science Review 2024年第7期11卷 135-147页

作者： Yue Zhao Wei Zhang Tiejun Li Center for Data Science Peking University Zuse Institute Berlin Department of Mathematics and Computer Science Freie Universit?t Berlin Laboratory of Mathematics and Applied Mathematics(LMAM)and School of Mathematical Sciences Peking University Center for Machine Learning research Peking University

We present EPR-Net, a novel and effective deep learning approach that tackles a crucial challenge in biophysics: constructing potential landscapes for high-dimensional non-equilibrium steady-state ***-Net leverages a nice mathematical fact that the desired negative potential gradient is simply the orthogonal projection of the driving force of the underlying dynamics in a weighted inner-product ***, our loss function has an intimate connection with the steady entropy production rate(EPR),enabling simultaneous landscape construction and EPR estimation. We introduce an enhanced learning strategy for systems with small noise, and extend our framework to include dimensionality reduction and the state-dependent diffusion coefficient case in a unified fashion. Comparative evaluations on benchmark problems demonstrate the superior accuracy, effectiveness and robustness of EPR-Net compared to existing methods. We apply our approach to challenging biophysical problems, such as an eight-dimensional(8D)limit cycle and a 52D multi-stability problem, which provide accurate solutions and interesting insights on constructed landscapes. With its versatility and power, EPR-Net offers a promising solution for diverse landscape construction problems in biophysics.

关键词： high-dimensional potential landscape non-equilibrium system entropy production rate dimensionality reduction deep learning

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Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

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National Science Review 2024年第3期11卷 14-16页

作者： Jia Si Panpan Zhang Zhiyong Zhang Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information photonics and Optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

关键词： TRANSISTORS

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An octopamine-specific GRAB sensor reveals a monoamine relay circuitry that boosts aversive learning

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National Science Review 2024年第5期11卷 186-201页

作者： Mingyue Lv Ruyi Cai Renzimo Zhang Xiju Xia Xuelin Li Yipan Wang Huan Wang Jianzhi Zeng Yifei Xue Lanqun Mao Yulong Li State Key Laboratory of Membrane Biology School of Life SciencesPeking University State Key Laboratory of Brain and Cognitive Science Institute of Biophysics Chinese Academy of Sciences PKU-IDG/Mc Govern Institute for Brain research Yuanpei College Peking University peking-Tsinghua Center for Life Sciences Academy for Advanced Interdisciplinary Studies Peking University peking university–Tsinghua university–National Institute of Biological Sciences Joint Graduate Program Academy for Advanced Interdisciplinary Studies Peking University Institute of Molecular Physiology Shenzhen Bay Laboratory College of Chemistry Beijing Normal University Chinese Institute for Brain research

Octopamine（OA）,analogous to norepinephrine in vertebrates,is an essential monoamine neurotransmitter in invertebrates that plays a significant role in various biological functions,including olfactory associative ***,the spatial and temporal dynamics of OA in vivo remain poorly understood due to limitations associated with the currently available methods used to detect *** overcome these limitations,we developed a genetically encoded GPCR activation-based（GRAB） OA sensor called *** sensor is highly selective for OA and exhibits a robust and rapid increase in fluorescence in response to extracellular *** GRABOA1.0,we monitored OA release in the Drosophila mushroom body（MB）,the fly's learning center,and found that OA is released in response to both odor and shock stimuli in an aversive learning *** OA release requires acetylcholine（ACh） released from Kenyon cells,signaling via nicotinic ACh ***,we discovered that OA amplifies aversive learning behavior by augmenting dopamine-mediated punishment signals via Octβ1R in dopaminergic neurons,leading to alterations in synaptic plasticity within the ***,our new GRABOA1.0sensor can be used to monitor OA release in real time under physiological conditions,providing valuable insights into the cellular and circuit mechanisms that underlie OA signaling.

关键词： octopamine dopamine GRAB sensor learning and memory

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Tuning the ferroelectricity of Hf0.5Zr0.5O2 with alloy electrodes

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Science China(Information Sciences) 2024年第8期67卷 321-330页

作者： Keqin LIU Bingjie DANG Zhiyu YANG Teng ZHANG Zhen YANG Jinxuan BAI Zelun PAN Ru HUANG Yuchao YANG Beijing Advanced Innovation Center for Integrated Circuits School of Integrated Circuits Peking University School of Electronic and Computer Engineering Peking University Center for Brain Inspired Chips Institute for Artificial Intelligence Peking University Center for Brain Inspired Intelligence Chinese Institute for Brain ResearchBeijing

Tuning ferroelectricity of Hf0.5Zr0.5O2is crucial for facilitating its practical applications in various fields, including in-memory and neuromorphic computing. Previous studies have revealed that the electrodes have a significant influence on ferroelectricity, and changing electrode materials can realize different but discrete ferroelectric polarization values. Here, we introduce an alloy-electrode method, in order to achieve gradual and accurate modulation of ferroelectric polarization, especially useful for matching the polarization charges at the interface of ferroelectric insulators and ferroelectric semiconductors. Au and W electrodes are chosen as baselines for realizing weak and strong ferroelectric polarization, where the intermediate states can be achieved by adjusting the ratio of metals in the Au-W alloy. To demonstrate the generality of this approach, the Cu-W alloy electrode is also realized for tuning ferroelectric polarization. The effect of alloy electrodes on device leakage current, endurance, and retention is evaluated. In addition, the temperature stability of ferroelectric capacitors is tested, where limited changes in both remnant polarization and coercive voltages are observed, showing the great potential of the ferroelectric hafnium oxide. Such gradual modulation of ferroelectric polarization could facilitate the application of Hf0.5Zr0.5O2in in-memory and neuromorphic computing.

关键词： ferroelectric hafnium oxide alloy electrode gradual modulation temperature stability

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Advances in functional MRI research in bipolar disorder:from the perspective of mood states

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General Psychiatry 2024年第1期37卷 33-43页

作者： Yankun Wu Yun-Ai Su Linlin Zhu Jitao Li Tianmei Si Department of Clinical Psychopharmacology Peking University Sixth HospitalPeking University Institute of Mental HealthNHC Key Laboratory of Mental Health(Peking University)National Clinical Research Center for Mental Disorders(Peking University Sixth Hospital)BeijingChina peking university Sixth Hospital Peking University Institute of Mental HealthNHC Key Laboratoryof Mental Health(Peking University)National Clinical Research Centerfor Mental Disorders(Peking University Sixth Hospital)BeijingChina

Bipolar disorder is characterised by recurrent and alternating episodes of mania/hypomania and *** breakthroughs in functional MRI techniques have uncovered the functional neuroanatomy of bipolar ***,the pathophysiology underlying mood instability,mood switching and the development of extreme mood states is less well *** reviewpresents a comprehensive overviewof current evidence from functional MRI studies from the perspective of mood *** first summarise the disrupted brain activation patterns and functional connectivity that have been reported in bipolar disorder,irrespective of the mood *** next focus on research that solely included patients in a single mood state for a better understanding of the pathophysiology of bipolar disorder and research comparing patients with different mood states to dissect mood state-related ***,we briefly summarise current theoretical models and conclude this review by proposing potential avenues for future research.A comprehensive understanding of the pathophysiology with consideration of mood states could not only deepen our understanding of how acute mood episodes develop at a neurophysiological level but could also facilitate the identification of biological targets for personalised treatment and the development of new interventions for bipolar disorder.

关键词： anatomy bipolar functional

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