STM EVIDENCE OF ROOM-TEMPERATURE CHARGE INSTABILITIES IN NBSE3

NbSe3 is a quasi-low-dimensional compound with unique properties. Two incommensurate charge-density waves appear at low temperatures, which slide under the application of an electric field. The mechanism of sli ding is not fully understood and it was speculated that precursor effe cts may be present above the onset temperatures. Scanning tunneling mi croscopy offers a unique tool to search for such charge instabilities and clear evidence is given for their existence at room temperature.