Modulation of Switching Characteristics in a Single VO 2 Nanobeam with Interfacial Strain via the Interconnection of Multiple Nanoscale Channels

We demonstrate the modulation of electrical switching properties through the interconnection of multiple nanoscale channels (∼600 nm) in a single VO nanobeam with a coexisting metal-insulator (M-I) domain configuration during phase transition. The Raman scattering characteristics of the synthesized VO nanobeams provide evidence that substrate-induced interfacial strain can be inhomogeneously distributed along the length of the nanobeam. Interestingly, the nanoscale VO devices with the same channel length and width exhibit distinct differences in hysteric current-voltage characteristics, which are explained by theoretical calculations of resistance change combined with Joule heating simulations of the nanoscale VO channels. The observed results can be attributed to the difference in the spatial distribution and fraction ratios of M-I domains due to interfacial strain in the nanoscale VO channels during the metal-insulator transition process. Moreover, we demonstrate the electrically activated resistive switching characteristics based on the hysteresis behaviors of the interconnected nanoscale channels, implying the possibility of manipulating multiple resistive states. Our results may offer insights into the nanoscale engineering of correlated phases in VO as the key materials of neuromorphic computing for which nonlinear conductance is essential.