无第二网络下的相互依赖网络临界性：$VO_2$中焦耳耦合绝缘体-金属转变的级联崩溃
Interdependent-Network Criticality without a Second Network: Cascading Collapse of the Joule-Coupled Insulator-Metal Transition in $VO_2$
- Bar Ilan University（巴伊兰大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
该研究揭示二氧化钒在电驱动下虽为单一结构却表现为相互依赖网络，焦耳耦合引发级联崩溃，实验与模型验证了临界指数，表明单一系统可展现相互依赖网络的灾难性级联行为。
AI中文摘要：
当受到足够大的电场或电流驱动时，二氧化钒（$VO_2$）的绝缘态通常在短暂的孵育延迟后突然崩溃为金属态（即绝缘体-金属转变，IMT）。这些孵育延迟通常持续微秒或更短，主要通过宏观电热模型进行分析，对转变动力学的统计洞察很少。在此，我们研究了二维$VO_2$晶格中电驱动的IMT，并证明该材料尽管是单一结构实体，却表现为复杂的相互依赖网络。由于金属区域比绝缘区域耗散更多的焦耳热，每次开关事件都会提高网络的焦耳加热，导致网络依赖性并触发级联链式反应。结合时间分辨电阻测量、焦耳耦合电阻网络模型和相互依赖网络理论，我们观察到在异常长的孵育平台（持续数千秒）之后出现突然（一级）转变。在这个亚稳态平台期间，开关活动的有效分支因子在临界点接近1，平台寿命以指数$\zeta=1/2$发散；序参量以指数$\beta=1/2$缩放。这些特征与相互依赖网络预测的特征一致，表明耗散性焦耳耦合单独就能在单网络关联氧化物系统中驱动混合阶灾难性级联。
英文摘要：
When driven by a large enough electric field or current, the insulating state of vanadium dioxide ($VO_2$) typically collapses abruptly into the metallic state (the insulator-metal transition, IMT) following a brief incubation delay. These incubation delays, typically lasting microseconds or less, have been analyzed predominantly through macroscopic electro-thermal modeling, providing little statistical insight into the transition dynamics. Here, we investigate the electrically driven IMT in a two-dimensional $VO_2$ lattice and demonstrate that the material behaves as a complex, interdependent network despite being a single structural entity. Because metallic domains dissipate significantly more Joule heat than insulating regions, each switching event raises the Joule heating of the network, resulting in network dependency and triggering a cascading chain reaction. Combining time-resolved resistance measurements with a Joule-coupled resistor-network model and interdependent-network theory, we observe an abrupt (first-order) transition preceded by an anomalously long incubation plateau lasting thousands of seconds. During this metastable plateau, an effective branching factor of the switching activity approaches unity at criticality, and the plateau lifetime diverges with exponent $ζ=1/2$; the order parameter scales with exponent $β=1/2$. These signatures coincide with those predicted for interdependent networks, indicating that dissipative Joule coupling alone can drive mixed-order catastrophic cascades in a single-network correlated-oxide system.
