posted on 2024-03-07, 14:39authored byUlysse Chazarin, Mahé Lezoualc’h, Abhishek Karn, Jyh-Ping Chou, Woei Wu Pai, Cyril Chacon, Yann Girard, Vincent Repain, Amandine Bellec, Sylvie Rousset, César González, Alexander Smogunov, Jérôme Lagoute, Yannick J. Dappe
Monolayer
transition metal dichalcogenide VTe2 exhibits
multiple charge density wave (CDW) phases, mainly (4 × 4) and
(4 × 1). Here we report facile dynamic and tens-of-nanometer
scale switching between these CDW phases with gentle bias pulses in
scanning tunneling microscopy. Bias pulses purposely stimulate a reversible
random CDW symmetry change between the isotropic (4 × 4) and
anisotropic (4 × 1) CDWs, as well as CDW phase slips and rotation.
The switching threshold of ∼1.0 V is independent of bias polarity,
and the switching rate varies linearly with the tunneling current.
Density functional theory calculations indicate that a coherent CDW
phase switching incurs an energy barrier of ∼2.0–3.0
eV per (4 × 4) unit cell. While there is a challenge in understanding
the observed large-area CDW random fluttering, we provide some possible
explanations. The ability to manipulate electronic CDW phases sheds
new light on tailoring CDW properties on demand.