Transport study of quasi-one dimensional transition metal trichalcogenides down to single-chain limit*

With the successful isolation of few-to-single layer of graphene and transition metal dichalcogenides (TMDs), two-dimensional van der Waals (vdW) materials have been a central focus in condensed matter physics and materials science.
In addition to 2D vdWs, a different class of 1D vdW materials, transition metal trichalcogenides (TMTs) such as NbSe₃, is emerging with recent advances in isolation and structural characterization of their few-to-single chain encapsulated within carbon and boron nitride nanotubes. The single chain limit of TMTs may exhibit novel physical phenomena, including unusual ground state and collective-mode electronic transport, for instance sliding charge density wave and superconductivity, as found in their bulk counterparts. However, the experimental investigation of these potential properties has been hindered by the challenge of nanodevice fabricating on such small samples. Here, we propose a new approach, correlating the structure-property of the few-to-single chain vdW materials by tranmission electron microscopy and device fabrication on the same individual chain-tube sample on a thin SiN membrane. Our work will open up new opportunities for study and application of 1D TMTs based electronics.