Ultrafast Triggering of Insulator–Metal Transition in Two-Dimensional VSe2

• DOI: 10.1021/acs.nanolett.0c04409
• Publication Date: 2021-02-19T11:32:26Z
• Authors: Deepnarayan Biswas; Alfred J. H. Jones; Paulina Majchrzak; Byoung Ki Choi; Tsung-Han Lee; Klara Volckaert; Jiagui Feng; Igor Marković; Federico Andreatta; Chang-Jong Kang; Hyuk Jin Kim; In Hak Lee; Chris Jozwiak; Eli Rotenberg; Aaron Bostwick; Charlotte E. Sanders; Yu Zhang; Gabriel Karras; Richard T. Chapman; Adam S. Wyatt; Emma Springate; Jill A. Miwa; Philip Hofmann; Phil D. C. King; Young Jun Chang; Nicola Lanatà; Søren Ulstrup
• Keywords: Charge Density Wave; Metal–insulator transition

Assembling transition metal dichalcogenides (TMDCs) at the two-dimensional (2D) limit is a promising approach for tailoring emerging states of matter such as superconductivity or charge density waves (CDWs). Single-layer (SL) VSe$_2$ stands out in this regard because it exhibits strongly enhanced CDW with higher temperature compared to bulk addition an insulating phase anisotropic gap Fermi level, causing suppression anticipated 2D ferromagnetism material. Here, we investigate interplay electronic and lattice degrees freedom that underpin these phases SL using ultrafast pump-probe photoemission spectroscopy. In state, observe light-induced closure energy on timescale 480 fs, which disentangle from ensuing hot carrier dynamics. Our work thereby reveals driven by electron-lattice coupling demonstrates potential controlling materials light.