  In one-dimensional (1D) metallic systems, the diverging electron
susceptibility and electron-phonon coupling collaboratively drive the electrons
into a charge density wave (CDW) state. However, strictly 1D system is unstable
against perturbations, whose effect on CDW order requires clarification ideally
with altered coupling to surroundings. Here, we fabricate such a system with
nanowires of Mo6Se6 bundles, which are either attached to edges of monolayer
MoSe2 or isolated freely, by post-annealing the preformed MoSe2. Using scanning
tunneling microscopy (STM), we visualized charge modulations and CDW gaps with
prominent coherent peaks in the edge-attached nanowires. Astonishingly, the CDW
order becomes suppressed in the isolated nanowires, showing CDW correlation
gaps without coherent peaks. The contrasting behavior, as revealed with
theoretical modeling, is interpreted as the effect of phason-polarons on the 1D
CDW state. Our work elucidates a possibly unprecedented many body effect that
may be generic to strictly 1D system but undermined in quasi-1D system.
