  Formation of charge-density-waves in ordered electronic phases (such as
charge-order) is an emergent phenomenon in the perovskite class of correlated
oxides. This scenario is visualized to prevail in exotic RNiO3 (R=rare-earth)
nickelates in which the structure controls the incipient charge-order to form
in weak localization limit. However, any consequent effect demonstrating these
nickelates in rare category of charge-density-waves conductors with controlled
charge-lattice interactions has been a fundamental challenge so-far. Here, we
present first evidence of the charge-density-waves in a prototypical NdNiO3
system employing terahertz time-domain spectroscopy along selective crystal
axes. A finite peak structure at 5meV in the terahertz conductivity displays
all the characteristics of a charge-density-wave condensate. Contrasting
charge-dynamics of collective charge-density-waves mode and Drude conductivity
emerging, respectively, from orthorhombic and cubic symmetries disentangle
charge-ordering from the insulating state, establish a novel structure-property
cause-effect relationship, and present opportunities to harness these diverse
attributes in oxide electronics.
