发表机构
Instituto de Nanociencia y Nanotecnología (INN), CONICET-CNEA; Centro Atómico Bariloche, Instituto Balseiro (UNCuyo), CONICET; Laboratorio de Ablación Láser (INN-CONICET-CNEA), Centro Atómico Constituyentes; Zernike Institute for Advanced Materials, University of Groningen; CogniGron Center, University of Groningen; Dept. de Física de la Materia Condensada, Universidad de Zaragoza; INMA—Instituto de Nanociencia y Materiales de Aragón, CSIC—Universidad de Zaragoza; Laboratorio de Microscopías Avanzadas, Universidad de Zaragoza（纳米科学与技术研究所（INN），阿根廷国家科学技术研究委员会-阿根廷原子能委员会; 巴里洛切原子中心，巴尔塞罗研究所（门多萨国立大学），阿根廷国家科学技术研究委员会; 激光烧蚀实验室（INN-CONICET-CNEA），宪法原子中心; 格罗宁根大学泽尼克先进材料研究所; 格罗宁根大学认知格罗宁根中心; 萨拉戈萨大学凝聚态物理系; 阿拉贡纳米科学与材料研究所（CSIC-萨拉戈萨大学）; 萨拉戈萨大学高级显微术实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过Ag修饰TaO$_x$忆阻器，利用Ag与氧空位动力学耦合，实现了突触抑制动力学的电学可编程调控，并在MNIST/Fashion-MNIST任务中验证了其功能。\n
AI 中文摘要
在忆阻神经形态硬件中，不仅工程化突触权重更新的幅度，而且工程化其动力学，是一项重要挑战。在此，我们表明，对TaO$_x$忆阻器进行Ag修饰，通过Ag相关动力学与氧空位动力学之间的相互作用，引入了突触抑制中一种电学可选择的自由度。参考器件表现出常规的双极开关，而Ag修饰器件则表现出对称的“桌腿”型磁滞回线、亚稳态中间态，以及抑制动力学对编程幅度的强非单调依赖。仅通过改变脉冲幅度，同一器件便可在三种状态之间驱动：逐渐的S形抑制、集中在少数脉冲内的突然更新，以及扩展到超过一百个脉冲的广泛分布演化。一个最小耦合态模型，其中空位相关的开关变量与较慢的Ag相关内部自由度相互作用，利用两个各自单调的场激活过程，再现了这种逐渐-突然-逐渐的交叉行为。功能影响在基于忆阻器的多层感知器中进行了评估。对于MNIST，突然、S形和缓慢演化的响应分别产生约50%、85%和88%的准确率，而逐渐状态在Fashion-MNIST上达到约72%。这些结果表明，耦合Ag相关和氧空位动力学可以将突触抑制从固定的器件特性转变为电学可编程的属性。
英文摘要
Engineering not only the magnitude but also the dynamics of synaptic weight updates is an important challenge for memristive neuromorphic hardware. Here, we show that Ag modification of TaO$_x$ memristors introduces an electrically selectable degree of freedom in synaptic depression through the interplay between Ag-related and oxygen-vacancy dynamics. Reference devices exhibit conventional bipolar switching, whereas Ag-modified devices display symmetric table-with-legs hysteresis loops, metastable intermediate states, and a strongly non-monotonic dependence of depression dynamics on programming amplitude. By varying only the pulse amplitude, the same device can be driven among three regimes: gradual sigmoidal depression, an abrupt update concentrated within a few pulses, and a broadly distributed evolution extending over more than one hundred pulses. A minimal coupled-state model, in which a vacancy-related switching variable interacts with a slower Ag-related internal degree of freedom, reproduces this gradual--abrupt--gradual crossover using two individually monotonic field-activated processes. The functional impact is assessed in a memristor-based multilayer perceptron. For MNIST, the abrupt, sigmoidal, and slowly evolving responses yield accuracies of approximately 50%, 85%, and 88%, respectively, while the gradual regime reaches approximately 72% for Fashion-MNIST. These results show that coupling Ag-related and oxygen-vacancy dynamics can transform synaptic depression from a fixed device characteristic into an electrically programmable property.
Comments27 pages, 7 figures
