Jo Minguk, Seo Ye-Won, Yoon Hyojin, Nam Yeon-Seo, Choi Si-Young, Choi Byung Joon, Son Junwoo
Department of Materials Science and Engineering (MSE), Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
Department of Chemical Engineering and Materials Science (CEMS), University of Minnesota, Minneapolis, MN, USA.
Nat Commun. 2022 Aug 10;13(1):4609. doi: 10.1038/s41467-022-32081-x.
Mott threshold switching, which is observed in quantum materials featuring an electrically fired insulator-to-metal transition, calls for delicate control of the percolative dynamics of electrically switchable domains on a nanoscale. Here, we demonstrate that embedded metallic nanoparticles (NP) dramatically promote metastability of switchable metallic domains in single-crystal-like VO Mott switches. Using a model system of Pt-NP-VO single-crystal-like films, interestingly, the embedded Pt NPs provide 33.3 times longer 'memory' of previous threshold metallic conduction by serving as pre-formed 'stepping-stones' in the switchable VO matrix by consecutive electical pulse measurement; persistent memory of previous firing during the application of sub-threshold pulses was achieved on a six orders of magnitude longer timescale than the single-pulse recovery time of the insulating resistance in Pt-NP-VO Mott switches. This discovery offers a fundamental strategy to exploit the geometric evolution of switchable domains in electrically fired transition and potential applications for non-Boolean computing using quantum materials.
莫特阈值开关现象出现在具有电激发绝缘体-金属转变特性的量子材料中，这需要在纳米尺度上精确控制电可切换畴的渗流动力学。在此，我们证明嵌入的金属纳米颗粒（NP）显著促进了类单晶VO莫特开关中可切换金属畴的亚稳性。有趣的是，通过使用Pt-NP-VO类单晶薄膜的模型系统，嵌入的Pt NPs通过在可切换VO矩阵中作为预先形成的“垫脚石”，在连续电脉冲测量中提供了比之前阈值金属传导长33.3倍的“记忆”；在低于阈值脉冲施加期间，之前激发的持久记忆在比Pt-NP-VO莫特开关中绝缘电阻单脉冲恢复时间长六个数量级的时间尺度上得以实现。这一发现为利用电激发转变中可切换畴的几何演化以及使用量子材料进行非布尔计算的潜在应用提供了一种基本策略。
