Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Ultrafast triggering of insulator-metal transition in two-dimensional
  VSe$_2$   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 a strongly enhanced CDW
transition with a higher transition temperature compared to the bulk in
addition to an insulating phase with an anisotropic gap at the Fermi level,
causing a suppression of anticipated 2D ferromagnetism in the material. Here,
we investigate the interplay of electronic and lattice degrees of freedom that
underpin these electronic phases in SL VSe$_2$ using ultrafast pump-probe
photoemission spectroscopy. In the insulating state, we observe a light-induced
closure of the energy gap on a timescale of 480 fs, which we disentangle from
the ensuing hot carrier dynamics. Our work thereby reveals that the phase
transition in SL VSe$_2$ is driven by electron-lattice coupling and
demonstrates the potential for controlling electronic phases in 2D materials
with light.

24
The categories of this paper are: dg-ga
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an
30
The categories of this paper are: q-alg
19
The categories of this paper are: eess
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
21
The categories of this paper are: adap-org
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin