Unidirectional charge-density-wave sliding in two-dimensional rare-earth tritellurides

Nonlinear transport properties in the layered TbTe3 and GdTe3 rare-earth tritellurides with a charge-density-wave (CDW) transition above room temperature have been studied along different crystallographic orientations. The pronounced effect of collective CDW motion is observed along c-axis and is absent completely in the perpendicular direction demonstrating the unidirectional character of the CDW. In contrast to one-dimensional CDWs the threshold electric field for CDW sliding is linearly temperature dependent in a wide range of temperature.