THERMOELECTRIC VOLTAGE STUDY OF 1T-TAS2 USING TEMPERATURE-DEPENDENT SCANNING TUNNELING SPECTROSCOPY

Using an ultra high vacuum (UHV) scanning tunneling microscope where t he sample is cooled while the tip remains close to room temperature, w e measured the thermoelectric voltage induced by the large thermal gra dient between the tip anti sample. Using tunneling thermometry techniq ue we studied the change of electronic structures of 1T-TaS2 front roo m temperature to 40 K. At the temperature for the nearly commensurate to commensurate transition, we found an abrupt change of tile thermoel ectric power from a very small value to about 0.15 mV/K.