Despite extensive studies on the insulator-to-metal transition (IMT) in strongly correlated VO2, the fundamental mechanism underlying the current-driven IMT in VO2 is still not well understood. Although it is generally believed that the mechanism is Joule heating leading to a rise in temperature to above the normal transition temperature, there is ample experimental evidence demonstrating that the transition could be driven by nonthermal electronic processes. Here we formulate a phase-field model to demonstrate that the electric current may drive the IMT isothermally via the current-induced electron-correlation weakening. We discover that a current with a large density (on the order of 10nA/nm2) induces ultrafast resistive switching on the order of a few nanoseconds, consistent with experimental measurements. We also construct the temperature-current phase diagram and investigate the influence of the current on domain walls. This work is expected to provide guidance for understanding the current-driven IMT in VO2 and for designing VO2-based electric switching devices.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)