  Resistive switching can be achieved in a Mott insulator by applying
current/voltage, which triggers an insulator-metal transition (IMT). This
phenomenon is key for understanding IMT physics and developing novel memory
elements and brain-inspired technology. Despite this, the roles of electric
field and Joule heating in the switching process remain controversial. We
resolve this issue by studying nanowires of two archetypical Mott insulators -
VO2 and V2O3. Our findings show a crossover between two qualitatively different
regimes. In one, the IMT is driven by Joule heating to the transition
temperature, while in the other, field-assisted carrier generation gives rise
to a doping driven IMT which is purely non-thermal. By identifying the key
material properties governing these phenomena, we propose a universal mechanism
for resistive switching in Mott insulators. This understanding enabled us to
control the switching mechanism using focused ion-beam irradiation, thereby
facilitating an electrically driven non-thermal IMT. The energy consumption
associated with the non-thermal IMT is extremely low, rivaling that of state of
the art electronics and biological neurons. These findings pave the way towards
highly energy-efficient applications of Mott insulators.

Strongly Correlated Electrons;Materials Science