Although the electrostatic tuning by three-terminal devices is generally weak for phase transition materials, it can control phases with much hither precision than temperature or pressure. This technique was applied to the scaled-down VO2 metal-insulator transitions, where the material phase is controlled by the gate voltage. The crossover from continuous to binary transition with scaling down was demonstrated, and the critical channel length was given by domain boundary instability. Interestingly, below the critical channel length, the influence of the noncritical stimulus (drain voltage in this case) disappeared because the spatial degree of freedom is lost in the single-domain VO2 channel.
- Takeaki Yajima
- Yusuke Samata
- Akira Toriumi