Electronic
Structure and Enhanced Charge-Density Wave
Order of Monolayer VSe<sub>2</sub>
Jiagui Feng
Deepnarayan Biswas
Akhil Rajan
Matthew D. Watson
Federico Mazzola
Oliver J. Clark
Kaycee Underwood
Igor Marković
Martin McLaren
Andrew Hunter
David M. Burn
Liam B. Duffy
Sourabh Barua
Geetha Balakrishnan
François Bertran
Patrick Le Fèvre
Timur K. Kim
Gerrit van der Laan
Thorsten Hesjedal
Peter Wahl
Phil D. C. King
10.1021/acs.nanolett.8b01649.s001
https://acs.figshare.com/articles/journal_contribution/Electronic_Structure_and_Enhanced_Charge-Density_Wave_Order_of_Monolayer_VSe_sub_2_sub_/6654170
How the interacting
electronic states and phases of layered transition-metal
dichalcogenides evolve when thinned to the single-layer limit is a
key open question in the study of two-dimensional materials. Here,
we use angle-resolved photoemission to investigate the electronic
structure of monolayer VSe<sub>2</sub> grown on bilayer graphene/SiC.
While the global electronic structure is similar to that of bulk VSe<sub>2</sub>, we show that, for the monolayer, pronounced energy gaps
develop over the entire Fermi surface with decreasing temperature
below <i>T</i><sub>c</sub> = 140 ± 5 K, concomitant
with the emergence of charge-order superstructures evident in low-energy
electron diffraction. These observations point to a charge-density
wave instability in the monolayer that is strongly enhanced over that
of the bulk. Moreover, our measurements of both the electronic structure
and of X-ray magnetic circular dichroism reveal no signatures of a
ferromagnetic ordering, in contrast to the results of a recent experimental
study as well as expectations from density functional theory. Our
study thus points to a delicate balance that can be realized between
competing interacting states and phases in monolayer transition-metal
dichalcogenides.
2018-06-18 00:00:00
use angle-resolved photoemission
single-layer limit
Enhanced Charge-Density Wave Order
low-energy electron diffraction
monolayer transition-metal dichalcogenides
charge-order superstructures
transition-metal dichalcogenides
observations point
energy gaps
T c
Monolayer VSe 2
Fermi surface
phase
Electronic Structure
monolayer VSe 2
charge-density wave instability
bulk VSe 2