Electronic states of domain structure in 1T-TaS2-xSe x observed by STM/STS

Abstract

We report on a systematic scanning tunneling microscopy and spectroscopy (STM/STS) study on 1T-TaS2-xSe x (x = 0, 0.3, 1.0) at 4.2 K. While the compounds with x = 0 and 0.3, which undergoes the Mott transition, showed the commensurate charge density wave (CDW) with the period of (a 0 is in-plane lattice constant), the compound with x=1, which shows superconductivity at 3.5 K, exhibits anomalous domain structure: The domain structure consists of regions with regular array of David-stars divided by bright contrasted walls at positive bias voltage. We found the domain wall showed the different electronic state from that of the domain.