  The metal-insulator transition (MIT) of bulk rare-earth nickelates is
accompanied by a simultaneous charge ordering (CO) transition. We have
investigated low-frequency resistance fluctuations (noise) across the MIT and
magnetic transition of [EuNiO$_3$/LaNiO$_3$] superlattices, where selective
suppression of charge ordering has been achieved by mismatching the
superlattice periodicity with the periodicity of charge ordering. We have
observed that irrespective of the presence/absence of long-range CO, the noise
magnitude is enhanced by several orders with strong non-1/$f$ ($f$ = frequency)
component when the system undergoes MIT and magnetic transition. The higher
order statistics of resistance fluctuations reveal the presence of strong
non-Gaussian components in both cases, further indicating inhomogeneous
electrical transport arising from the electronic phase separation.
Specifically, we find almost three orders of magnitude smaller noise in the
insulating phase of the sample without long-range CO compared to the sample
with CO. These findings suggest that digital synthesis can be a potential route
to implement electronic transitions of complex oxides for device application.
