Resistive-memory devices promise to revolutionize modern computer architecture eliminating the data-shuttling bottleneck between the memory and processing unit. Recent years have seen a surge of experimental demonstrations of such devices built upon two-dimensional materials based metal–insulator–metal structures. However, the fundamental mechanism of nonvolatile resistive switching has remained elusive. Here, we conduct reactive molecular dynamics simulations for a sulfur vacancy inhabited monolayer molybdenum disulfide-based device with inert electrode systems to gain insight into such phenomena. We observe that with the application of a suitable electric field, at the vacancy positions, the sulfur atom from the other plane pops and gets arrested in the plane of the molybdenum atoms. Rigorous first principles based calculations surprisingly reveal localized metallic states (virtual filament) and stronger chemical bonding for this new atomic arrangement, explaining the nonvolatile resistive switching. We further observe that localized Joule heating plays a crucial role in restoring the popped sulfur atom to its original position. The proposed theory, which delineates both unipolar and bipolar switching, may provide useful guidelines for designing high-performance resistive-memory-based computing architecture.

电阻存储器设备有望彻底改变现代计算机体系结构，消除存储器和处理单元之间的数据穿梭瓶颈。近年来，已经在基于二维材料的金属-绝缘体-金属结构上建立了这种设备的实验性演示。但是，非易失性电阻开关的基本机制仍然难以捉摸。在这里，我们对具有惰性电极系统的硫空位单层二硫化钼单层器件进行了反应分子动力学模拟，以深入了解此类现象。我们观察到，通过施加适当的电场，在空位处，来自另一个平面的硫原子突然弹出并被捕集在钼原子的平面中。严格的基于第一原理的计算令人惊讶地揭示了这种新原子排列的局部金属态（虚拟灯丝）和更强的化学键合，从而说明了非易失性电阻切换。我们进一步观察到，局部焦耳加热在将弹出的硫原子恢复到其原始位置方面起着至关重要的作用。提出的理论描述了单极性和双极性切换，可以为设计高性能基于电阻性存储器的计算架构提供有用的指导。