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O: Fachverband Oberflächenphysik
O 99: Gerhard Ertl Young Investigator Award: Finalists session
O 99.2: Talk
Thursday, March 4, 2021, 14:00–14:30, R1
Ab-initio studies of exciton g factors: Monolayer transition metal dichalcogenides in magnetic fields — •Thorsten Deilmann, Peter Krüger, and Michael Rohlfing — Institute of Solid State Theory, University of Münster, Germany
The effect of a magnetic field on the optical absorption in semiconductors
has been measured experimentally and modeled theoretically for various systems
in previous decades.
We present a new first-principles approach [1]
to systematically determine the response of excitons to magnetic fields, i.e. exciton g factors.
By utilizing the GW-Bethe-Salpeter equation methodology
we show that g factors extracted from the Zeeman shift of electronic bands
are strongly renormalized by many-body effects
which we trace back to the extent of the excitons in reciprocal space.
We apply our approach to
monolayers of transition metal dichalcogenides (MoS2, MoSe2, MoTe2, WS2, and WSe2)
with strongly bound excitons
for which g factors are weakened by about 30%.
[1] Phys. Rev. Lett. 124, 226402 (2020)