Electric current has been experimentally demonstrated to be able to drive the insulator-to-metal transition (IMT) in VO2. The main mechanisms involved are believed to be the Joule heating effect and the strong electron-correlation effect. These effects are often entangled with each other in experiments, which complicates the understanding of the essential nature of the observations. We formulate a phase-field model to investigate theoretically in mesoscale the pure correlation effect brought by the current on the IMT in VO2, i.e., the isothermal process under the current. We find that a current with a large density (∼101 nA/nm2) induces a few-nanosecond ultrafast switch in VO2, in agreement with the experiment. The temperature-current phase diagram is further calculated, which reveals that the current may induce the M2 phase at low temperatures. The current is also shown capable of driving domain walls to move. Our work may assist related experiments and provide guidance to the engineering of VO2-based electric switching devices.
@article{arxiv.1809.05549,
title = {Isothermal current-driven insulator-to-metal transition in VO$_\text{2}$ through strong correlation effect},
author = {Yin Shi and Long-Qing Chen},
journal= {arXiv preprint arXiv:1809.05549},
year = {2019}
}