发表机构
National Center for Nanoscience and Technology, Chinese Academy of Sciences; University of Chinese Academy of Sciences; Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences; Songshan Lake Materials Laboratory; College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University（中国科学院国家纳米科学中心; 中国科学院大学; 中国科学院物理研究所北京凝聚态物理国家研究中心; 松山湖材料实验室; 北京师范大学化学学院教育部理论计算光化学重点实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过面外振荡电场在准二维AgCrSe2中实现低温非平衡超离子传输，在300 K下获得约1.7 S/cm的离子电导率，揭示了时间尺度匹配的周期性驱动作为远低于平衡转变温度下激活离子无序的途径。
AI 中文摘要
超离子导体能够在固体中实现极快的离子传输，并具有广泛的技术应用潜力。然而，其高导电态通常仅在移动离子亚晶格的有序-无序转变温度以上才能实现，这限制了其在低温下的应用。在此，电场响应型机器学习分子动力学揭示了一种非平衡路径，通过面外振荡电场在准二维AgCrSe2中实现超离子传输。在300 K（远低于约475 K的转变温度）下，该电场激活了快速的平面内Ag+传输，离子电导率达到约1.7 S/cm。这源于电场驱动的Ag+在两个等价亚晶格间的动态无序，而非热诱导的无序化。随着频率增加，Ag占据态从完全切换演变为高导电的动态无序态，最终转变为对电场响应较弱的有序态。这些状态区间随温度或电场振幅的增加而向更高频率移动，这与驱动周期和Ag亚晶格响应时间之间的竞争一致。在强电场下，该时间尺度与电场辅助的热激活一致，而弱电场下的偏差则表明存在超出单离子激活的额外动力学。这些结果表明，时间尺度匹配的周期性驱动是在远低于平衡超离子转变温度下实现传输活性离子无序的一种途径。
英文摘要
Superionic conductors enable exceptionally fast ion transport in solids and offer broad technological potential. However, their highly conductive states are typically accessed only above the order-disorder transition of the mobile-ion sublattice, which limits low-temperature operation. Here, electric-field-responsive machine-learning molecular dynamics reveals a nonequilibrium route to superionic transport in quasi-two-dimensional AgCrSe2 driven by an out-of-plane oscillating electric field. At 300 K, far below the transition temperature near 475 K, the field activates fast in-plane Ag+ transport with an ionic conductivity reaching ~1.7 S/cm. This originates from field-driven dynamic disorder of Ag+ across two equivalent sublattices rather than thermally induced disordering. With increasing frequency, the Ag occupation evolves from complete switching to a highly conductive dynamically disordered state and finally to an ordered state with weak field response. These regimes shift to higher frequencies with increasing temperature or field amplitude, consistent with competition between the driving period and Ag-sublattice response time. At strong fields, this timescale is consistent with field-assisted thermal activation, while weak-field deviations suggest additional dynamics beyond single-ion activation. These results suggest timescale-matched periodic driving as a route to transport-active ionic disorder far below an equilibrium superionic transition.
