TY - JOUR
T1 - Electronic structure of chromium trihalides beyond density functional theory
AU - Acharya, Swagata
AU - Pashov, Dimitar
AU - Cunningham, Brian
AU - Rudenko, Alexander N.
AU - Rösner, Malte
AU - Grüning, Myrta
AU - Schilfgaarde, Mark van
AU - Katsnelson, Mikhail I.
PY - 2021/10/5
Y1 - 2021/10/5
N2 - We explore the electronic band structure of freestanding monolayers of chromium trihalides CrX3, X = Cl,
Br, I, within an advanced ab initio theoretical approach based on the use of Green’s function functionals. We
compare the local density approximation with the quasiparticle self-consistent GW (QSGW) approximation and
its self-consistent extension (QSGW) by solving the particle-hole ladder Bethe-Salpeter equations to improve
the effective interaction W. We show that, at all levels of theory, the valence band consistently changes shape in
the sequence Cl→Br →I, and the valence band maximum shifts from the M point to the point. By analyzing
the dynamic and momentum-dependent self-energy, we show that QSGW adds to the localization of the systems
in comparison with QSGW, thereby leading to a narrower band and reduced amount of halogens in the valence
band manifold. Further analysis shows that X = Cl is most strongly correlated, and X = I is least correlated
(most bandlike) as the hybridization between Cr d and X p enhances in the direction Cl→Br →I. For CrBr3
and CrI3, we observe remarkable differences between the QSGW and QSGW valence band structures, while
their eigenfunctions are very similar. We show that weak perturbations, like moderate strain, weak changes to
the d-p hybridizati
AB - We explore the electronic band structure of freestanding monolayers of chromium trihalides CrX3, X = Cl,
Br, I, within an advanced ab initio theoretical approach based on the use of Green’s function functionals. We
compare the local density approximation with the quasiparticle self-consistent GW (QSGW) approximation and
its self-consistent extension (QSGW) by solving the particle-hole ladder Bethe-Salpeter equations to improve
the effective interaction W. We show that, at all levels of theory, the valence band consistently changes shape in
the sequence Cl→Br →I, and the valence band maximum shifts from the M point to the point. By analyzing
the dynamic and momentum-dependent self-energy, we show that QSGW adds to the localization of the systems
in comparison with QSGW, thereby leading to a narrower band and reduced amount of halogens in the valence
band manifold. Further analysis shows that X = Cl is most strongly correlated, and X = I is least correlated
(most bandlike) as the hybridization between Cr d and X p enhances in the direction Cl→Br →I. For CrBr3
and CrI3, we observe remarkable differences between the QSGW and QSGW valence band structures, while
their eigenfunctions are very similar. We show that weak perturbations, like moderate strain, weak changes to
the d-p hybridizati
U2 - 10.1103/PhysRevB.104.155109
DO - 10.1103/PhysRevB.104.155109
M3 - Article
SN - 2469-9950
VL - 104
JO - Physical Review B
JF - Physical Review B
IS - 15
M1 - 155109
ER -