Photo-induced enhancement of charge density wave current in the quasi-one-dimensional conductor TaS_3

摘要

In the near vicinity of Peicrls transition temperature T_p, we have measured the Ⅴ-Ⅰcharacteristics of the quasi-one-dimensional conductor TaS_3 under dark and photo-irradiation conditions. It is found that a significant enhancement of CDW current occurs only around the threshold voltage V_t under photo-irradiation. This effect can be interpreted as a result of screening of pinning potential for CDW condensate by photo-excited quasi-particlcs (QP' s). Further the distribution of pinning potential intensity is reflected in the behavior of Ⅴ-Ⅰ characteristics near V_t. Our finding suggests that the strength of pinning potential can be controlled by the photo-excited QP's in quasi-1D conductors.