Soliton Analysis of the Electro-Optical Response of Blue Bronze

In recent measurements on the charge-density-wave (CDW) conductor blue bronze (K0.3MoO3), the electro-transmittance and electro-reflectance spectra were searched for intragap states that could be associated with solitons created by injection of electrons into the CDW at the current contacts [Eur. Phys. J. B 16, 295 (2000); ibid 35, 233 (2003)]. In this work, we adapt the model of soliton absorption in dimerized polyacetylene to the blue bronze results, to obtain the (order of magnitude) estimate that current induced solitons occur on less than ~ 10% of the conducting chains. We discuss the implications of these results on models of soliton lifetimes and motion of CDW phase dislocations.