Remotely triggered resistive switching in multiterminal VO₂ devices

In resistive switching, a device is switched between two or more resistance states by (pulsed) external stimuli, typically of electric, optical, or thermal origin. Devices with this property are of interest for rapidly developing, energy-efficient computing paradigms – e.g., in-memory and neuromorphic computing – envisioned to meet the computing demands of the AI revolution in a sustainable manner.
A variety of (often intertwining) material properties and physical processes underlies resistive switching behavior: for example, ionic transport, redox reactions, ferroic domain order and motion, spin alignment, structural phase transitions, electronic phase transitions, and filament formation [1]. Developing and applying an in-depth understanding of these properties and processes allows engineering new functionality in devices with specially designed geometries.

Here, we expand the typical two-terminal device geometry by adding a third electric terminal, which enables triggering remotely a resistive switch between the two other terminals. This effect hinges on the thermal hysteresis, filament formation, and reversibility inherent to the electrically triggered insulator-to-metal transition in the active material, VO2 [2]. Contrary to local resistive switching between any two terminals in our device, the remotely triggered switch persists after the stimulus on the third terminal is removed. Both current and voltage as well as mixed stimuli can trigger the remote switch, allowing same-quantity gain or voltage-current interconversion. The remote effect is observed if a ‘drain-source’ bias is applied within the hysteresis loop observed for two-terminal switching. In the middle of this region, the change in channel resistance induced by the remote switch is maximized at ~2500%.

Multiphysics simulations show that the thermal crosstalk between filaments – previously observed for parallel two-terminal devices [3] – drives the remote switch. Moreover, tuning the applied biases enables controlling the pathways taken by the filaments, realizing filament patterns that depend on the device history in a complex manner. These devices pave the way for realizing reconfigurable logic [4] inherently at room temperature and provide a multidimensional platform for studying the dynamics of the electronically triggered metal-to-insulator transition in VO2 and related materials.