Decoupling of IMT and SPT for Mott Transition in Strained VO2 Films on AlN/Si

Insulator-to-metal transition (IMT) in a strongly correlated material VO$_{\mathrm{2}}$ is under the gaze of scientists, attempting to obtain the solely electronic Mott transition without any structural intervention in the vicinity of room temperature. It would open up the numerous prospects for application, for example, Mott field effect transistor able to overcome the size and switching speed limitations of the Si-based transistors Moreover, synergy of VO$_{\mathrm{2}}$ and existing silicon technology can provide inexpensive mass production of the new generation switching devices. In this work, using the high-quality epitaxial VO$_{\mathrm{2}}$ films, successfully integrated with Si, we were able to delay IMT and structural phase transition (SPT) by strain engineering and to decouple this two processes. In particular, through simultaneous monitoring of evolution of the IMT and SPT with temperature we obtained the evidence of the electron-correlation-driven Mott transition in VO$_{\mathrm{2}}$ (IMT precedes SPT for up to 10 K!) occurring in the same monoclinic crystalline structure.