REENTRANT CHARGE-DENSITY WAVE IN THE ONE-DIMENSIONAL SYSTEM WITH IMPURITIES - A SELF-CONSISTENT APPROACH

We investigate here how the CDW and the distribution of non-magnetic impurities affect each other. The former is assumed to induce a distortion of the latter having the same wave vector. This CDW-induced distortion yields an enhancement of CDW which competes to the usual destructive effect via electronic life-time. The behaviour of relevant quantities changes in a non-trivial manner as compared to the case of perfectly random inpurity distribution. Depending on the values of the various coupling strengths of the problem, a reentrant CDW can be obtained by increasing the impurity concentration. The conditions for occurrence of the gapless CDW state are also modified. Thermal hysteresis effects are suggested for the doped quasi-1D conductors. Data reported for a variety of compounds ((CH)x, NbSe3, deuterated thiourea, (TMTSF)2X) are interpreted within the present model. © 1990 IOP Publishing Ltd.