We show that the charge density wave (CDW) ground state below the Peierls
transition temperature, TCDW​, of rare-earth tritellurides is not at its
equilibrium value, but depends on the time where the system was kept at a fixed
temperature below TCDW​. This ergodicity breaking is revealed by the
increase of the threshold electric field for CDW sliding which depends
exponentially on time. We tentatively explain this behavior by the
reorganization of the oligomeric (Tex​)2− sequence forming the CDW
modulation.Comment: 10 pages, 5 figures, accepted in PR