  Non-equilibrium steady state (NESS) conditions induced by DC current can
alter the physical properties of strongly correlated electron systems (SCES).
In this regard, it was recently shown that DC current can trigger novel
electronic states, such as current-induced diamagnetism, which cannot be
realized in equilibrium conditions. However, reversible control of diamagnetism
has not been achieved yet. Here, we demonstrate reversible in situ control
between a Mott insulating state and a diamagnetic semimetal-like state by DC
current in the Ti-substituted bilayer ruthenate
Ca$_3$(Ru$_{1-x}$Ti$_x$)$_2$O$_7$ ($x=0.5$%). By performing simultaneous
magnetic and resistive measurements, we map out the temperature vs
current-density phase diagram in the NESS of this material. The present results
open up the possibility of creating novel electronic states in a variety of
SCES under DC current.
