  Strongly correlated materials that exhibit an insulator-metal transition are
key candidates in the search for new computing platforms. Understanding the
pathways and timescales underlying the electrically-driven insulator-metal
transition is crucial for uncovering the fundamental limits of device
operation. Using stroboscopic electron diffraction, we perform synchronized
time-resolved measurements of atomic motions and electronic transport in
operating vanadium dioxide switches. We discover an electrically-triggered,
isostructural state that forms transiently on microsecond timescales,
stabilized by local heterogeneities and interfacial interactions between the
equilibrium phases. This metastable phase bears striking similarity to that
formed under photoexcitation within picoseconds, suggesting a universal
transformation pathway across eight orders of magnitude of timescale. Our
results establish a new route for uncovering non-equilibrium and metastable
phases in correlated materials, and open avenues for engineering novel
dynamical behavior in nanoelectronics.
