金属/铌掺杂锶钛氧（Nb:SrTiO$_3$）中的阻变与神经形态计算：机制、界面物理与电荷输运
Resistive Switching and Neuromorphic Computing in Metal/Nb:SrTiO$_3$: Mechanisms, Interface Physics, and Charge Transport
AI总结：
本综述针对金属/Nb:STO异质结的阻变机制争议，提出以界面层演化的统一框架解释实验观测，总结相关影响因素，为可靠氧化物忆阻器件提供设计准则。
AI中文摘要：
基于铌掺杂锶钛氧（Nb:STO）的忆阻器件中的阻变（RS）因具有无需成形操作、高开关比及渐进式电导调制特性，在信息处理与新型计算领域持续受到关注。金属/Nb:STO肖特基结已成为研究RS机制的典型体系。尽管历经二十余年研究，RS的物理起源仍存在争议，已提出的机制包括电荷捕获与去捕获、氧空位迁移、隧穿、界面氧化还原反应及导电细丝形成。本综述审视这些看似相互矛盾的机制，表明许多实验观测可通过以金属/Nb:STO界面处外来界面层的形成与演化为核心的统一框架来解释。我们探讨界面质量与缺陷介导过程（包括质子掺入、氧空位动力学及隧穿）如何调控肖特基势垒与RS行为。我们还总结制备条件、测量方案及老化如何影响界面形成与开关特性。本综述建立了金属/Nb:STO异质结的整合图景，并为金属/Nb:STO及金属/氧化物/Nb:STO体系中通过界面与缺陷工程设计可靠氧化物忆阻器件提供了设计准则。
英文摘要：
Resistive switching (RS) in Nb-doped SrTiO$_3$ (Nb:STO) based memristive devices has attracted sustained interest in information processing and novel computing because of its forming-free operation, large on/off ratio, and gradual conductance modulation. Metal/Nb:STO Schottky junctions have emerged as a prototypical system for understanding RS mechanisms. Despite more than two decades of research, the physical origin of RS remains controversial, with proposed mechanisms including charge trapping and detrapping, oxygen vacancy migration, tunneling, interfacial redox reactions, and conductive filament formation. In this review, we examine these seemingly competing mechanisms and show that many experimental observations can be understood within a unified framework centered on the formation and evolution of an extrinsic interfacial layer at the metal/Nb:STO interface. We discuss how interface quality and defect-mediated processes, including proton incorporation, oxygen vacancy dynamics, and tunneling, govern Schottky barrier modulation and RS behavior. We further summarize how fabrication conditions, measurement protocols, and aging influence the interface formation and switching characteristics. This review establishes an integrated picture of M/Nb:STO heterojunctions and provides design principles for reliable oxide memristive devices through interface and defect engineering in M/Nb:STO and M/oxide/Nb:STO systems.
