Sliding charge density waves without damping: Possible fröhlich superconductivity in blue bronze

We observed zero differential resistance in K 0.3Mo0 3 in the temperature range of 4.2–40 K. It appears above a contact dependent barrier voltage. At 4.2 K the current can be increased from 50 nA to 1A without observable change in voltage. By measuring narrow band noise spectra at different current levels we show that the phenomenon arises from undamped sliding of charge density waves.