nanodevices*

VO₂ and V₂O₃ are two classical examples of strongly electron-correlated materials, showing an Insulator-Metal transition (IMT) at 340 K and 160 K respectively. The possibility to induce the IMT using electric current or voltage has made them attractive for applications in emerging technologies such as RRAM memories or neuromorphic computing. We have studied the dynamics of the IMT in VO_X nanodevices using fast voltage pulses. We found that above a threshold voltage (V_th), the IMT is induced within a few nanoseconds, after which the device returns to the insulating state in less than 10 ns. Interestingly, the system retains a “memory” of the event that persists much longer, during which it is possible to trigger the IMT with voltages well below V_th. This effect opens the possibility for a new kind of volatile memory, and it could have important implications for the implementation of IMT-based neuristors or RRAMs.