  We experimentally investigate transport properties of a hybrid structure,
which consists of a thin single crystal SnSe flake on a top of 5~$\mu$m spaced
Au leads. The structure initially is in highly-conductive state, while it can
be switched to low-conductive one at high currents due to the Joule heating of
the sample, which should be identified as $\alpha$-$Pnma$ -- $\beta$-$Cmcm$
diffusionless martensitic phase transition in SnSe. For highly-conductive
state, there is significant hysteresis in $dI/dV(V)$ curves at low biases, so
the sample conductance depends on the sign of the applied bias change. This
hysteretic behavior reflects slow relaxation due to additional polarization
current in the ferroelectric SnSe phase, which we confirm by direct measurement
of time-dependent relaxation curves. In contrast, we observe no noticeable
relaxation or low-bias hysteresis for the quenched $\beta$-$Cmcm$
low-conductive phase. Thus, ferroelectric behavior can be switched on or off in
transport through hybrid SnSe structure by controllable $\alpha$-$Pnma$ --
$\beta$-$Cmcm$ phase transition. This result can also be important for
nonvolatile memory development, e.g. phase change memory for neuromorphic
computations or other applications in artificial intelligence and modern
electronics.
