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@ARTICLE{Ramezani:1025706,
author = {Ramezani, H. R and Şaşıoğlu, E. and Hadipour, H. and
Soleimani, H. Rahimpour and Friedrich, Christoph and
Blügel, Stefan and Mertig, I.},
title = {{N}onconventional screening of {C}oulomb interaction in
two-dimensional semiconductors and metals: {A} comprehensive
constrained random phase approximation study of {M} {X} 2 (
{M} = {M}o , {W} , {N}b , {T}a ; {X} = {S} ,
{S}e , {T}e )},
journal = {Physical review / B},
volume = {109},
number = {12},
issn = {2469-9950},
address = {Woodbury, NY},
publisher = {Inst.},
reportid = {FZJ-2024-03089},
pages = {125108},
year = {2024},
abstract = {Two-dimensional (2D) semiconducting and metallic transition
metal dichalcogenides (TMDs) have attracted significant
attention for their promising applications in a variety of
fields. Experimental observations of large exciton binding
energies and nonhydrogenic Rydberg series in 2D
semiconducting TMDs, along with deviations in plasmon
dispersion in 2D metallic TMDs, suggest the presence of a
nonconventional screening of the Coulomb interaction. The
experimentally observed Mott insulating state in the charge
density wave (CDW) reconstructed lattice of TMDs containing
4d and 5d elements further confirms the presence of strong
Coulomb interactions in these systems. In this study, we use
first-principles electronic structure calculations and
constrained random-phase approximation to calculate the
Coulomb interaction parameters (partially screened U and
fully screened W) between localized d electrons in 2D TMDs.
We specifically explore materials represented by the formula
MX2 (M=Nb, Ta, Mo, W; X=S, Se, Te) and consider three
different phases (1H, 1T, and 1T′). Our results show that
the short-range interactions are strongly screened in all
three phases, whereas the long-range interactions remain
significant even in metallic systems. This nonconventional
screening provides a compelling explanation for the
deviations observed in the usual hydrogenic Rydberg series
and conventional plasmon dispersion in 2D semiconducting and
metallic TMDs, respectively. Our calculations yield on-site
Coulomb interaction parameters U within the ranges of
0.8–2.5, 0.8–1.9, and 0.9–2.4 eV for the 1H, 1T, and
1T′ structures, respectively. These values depend on the
specific chalcogen X, the number of d electrons, and the
correlated subspace. Using the calculated U parameters for
the undistorted 1T structure, we extract the on-site
effective Ueff00 and nearest-neighbor Ueff01 Coulomb
interaction parameters for reconstructed commensurate CDW
NbX2 and TaX2 compounds. Furthermore, our findings indicate
a substantially high ratio of on-site effective Coulomb
interaction to bandwidth (Ueff00/Wb≫1) in CDW TMDs,
providing robust evidence for the experimentally observed
strongly correlated Mott phase. This work sheds light on the
nonconventional screening of Coulomb interactions in 2D
TMDs, offering valuable insights into their electronic
properties and potential applications in emerging
technologies. It advances our fundamental understanding of
these materials and holds promise for their use in various
applications.},
cin = {PGI-1},
ddc = {530},
cid = {I:(DE-Juel1)PGI-1-20110106},
pnm = {5211 - Topological Matter (POF4-521)},
pid = {G:(DE-HGF)POF4-5211},
typ = {PUB:(DE-HGF)16},
UT = {WOS:001235184300003},
doi = {10.1103/PhysRevB.109.125108},
url = {https://juser.fz-juelich.de/record/1025706},
}