基于二维晶体的阻变实现非马尔可夫过程

Realization of a non-markov chain in a single 2D mineral RRAM

在大数据时代,具有历史累积效应的非马尔可夫链算法显得尤为重要,如与记忆相关的人类脑神经、与环境相关的量子纠缠态和机器视觉追踪算法等.在传统的器件结构中,需通过大量晶体管和存储器的协同作用才能实现这类功能.基于二维材料的电阻随机存取存储器(RRAM)在下一代计算系统中已显示出巨大的应用潜力,为非马尔可夫链的简易实现提供了解决方案.本文发现二维云母片是一种良好的离子导体,其内部的钾离子可在外加电场的驱动下定向移动,使云母表现出阻变特征.进一步研究发现云母RRAM兼具单、双存储窗口,高开关比,良好的稳定性和重复性等优点.基于云母RRAM首次在单个存储器件中实现了非马尔可夫过程,其输出状态既取决于当前输入电压的极性,也取决于之前所施加电压的极性.本文利用RRAM器件中导电离子的极性在硬件系统中实现了非马尔可夫过程,对未来人工智能和大数据算法等领域的发展具有一定意义.

The non-Markov process exists widely in thermodymanic process,while it usually requires the packing of many transistors and memories with great system complexity in a traditional device structure to minic such functions.Two-dimensional(2D)material-based resistive random access memory(RRAM)devices have the potential for next-generation computing systems with much-reduced complexity.Here,we achieve a non-Markov chain in an individual RRAM device based on 2D mineral material mica with a vertical metal/mica/metal structure.We find that the potassium ions(K+)in 2D mica gradually move in the direction of the applied electric field,making the initially insulating mica conductive.The accumulation of K+is changed by an electric field,and the 2D-mica RRAM has both single and double memory windows,a high on/off ratio,decent stability,and repeatability.This is the first time a non-Markov chain process has been established in a single RRAM,in which the movement of K+is dependent on the stimulated voltage as well as their past states.This work not only uncovers an intrinsic inner ionic conductivity of 2D mica,but also opens the door for the production of such RRAM devices with numerous functions and applications.