Studying the near-room temperature insulator-to-metal switching in ultrathin VO2 films on (001) TiO2

The insulator-to-metal-transition (IMT) switching in VO2 is intriguing for science and promising for technology. Nevertheless, there is a lack of understanding the physical mechanism behind the IMT switching due to its coupling to the structural changes. Here we study the thermally-driven phase transition switching in ultrathin VO2 films on rutile (001) $\text{TiO}_{2}$ substrates, which is tuned to occur near room temperature by the substrate-induced strain in the films. We show that if the VO2 thickness is about 5 nm, it is possible to implement its IMT switching in the same structure, independent of the structural change. This is a promising core technology of the IMT switching and neuromorphic devices.