Charge Density Waves and Superconductivity at the Single-layer Limit in NbSe2
First atomic-scale study of single-layer NbSe2. The coexistence of charge density wave (CDW) order and superconductivity have been confirmed at the single-layer limit for a 2D transition metal dichalcogenide material.
Significance and Impact
The manybody ground state of NbSe2 has been clarified, allowing quantitative exploration of the interplay between collective phenomena in reduced dimensions.
- The electronic CDW pattern in single-layer NbSe2 was imaged by atomically-resolved scanning tunneling microscopy.
- The simplified band structure of single-layer NbSe2 was determined using angle-resolved photoemission (ARPES ) and scanning tunneling spectroscopy (STS), enabling different theories for the ground state of NbSe2 to be ruled out.
- Superconductivity in single-layer NbSe2 was found at 1.9 K via transport measurement, revealing NbSe2 to be one of the few 2D materials that can exhibit superconductivity in isolation.