Anisotropic band splitting in monolayer NbSe₂: implications for superconductivity and charge density wave

Anisotropic band splitting in monolayer NbSe2: implications for superconductivity and charge density waveAnisotropic band splitting in monolayer NbSe₂: implications for superconductivity and charge density wave, Published online: 03 May 2018; doi:10.1038/s41699-018-0057-3The interplay between symmetry breaking, superconductivity and charge density wave in monolayer NbSe2 is unveiled by spectroscopic techniques. A team led by Takafumi Sato at Tohoku University used molecular beam epitaxy to fabricate atomically thin NbSe2 films on bilayer graphene, and investigated their electronic properties by a combination of electrical transport measurements, scanning tunneling microscopy, and angle-resolved photoemission spectroscopy. A charge density wave transition with a strong periodic charge modulation was detected below 1.5 K, accompanied by the emergence of superconductivity. Owing to the inversion symmetry breaking occurring in monolayer NbSe2, a band splitting developed along the Γ-Κ direction of the Brillouin zone. Such band splitting was found to be related to the robustness of the observed superconductivity, as well as the formation of the charge density wave.

Published in: "NPJ 2D Materials and Applications".