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Title: Ab initio calculations of spin-nonconserving exciton–phonon scattering in monolayer transition metal dichalcogenides
Abstract We investigate the spin-nonconserving relaxation channel of excitons by their couplings with phonons in two-dimensional transition metal dichalcogenides using ab initio approaches. Combining GW-Bethe–Salpeter equation method and density functional perturbation theory, we calculate the electron–phonon and exciton–phonon coupling matrix elements for the spin-flip scattering in monolayer WSe 2 , and further analyze the microscopic mechanisms influencing these scattering strengths. We find that phonons could produce effective in-plane magnetic fields which flip spin of excitons, giving rise to relaxation channels complimentary to the spin-conserving relaxation. Finally, we calculate temperature-dependent spin-flip exciton–phonon relaxation times. Our method and analysis can be generalized to study other two-dimensional materials and would stimulate experimental measurements of spin-flip exciton relaxation dynamics.  more » « less
Award ID(s):
1719797
NSF-PAR ID:
10322827
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Journal of Physics: Condensed Matter
Volume:
34
Issue:
26
ISSN:
0953-8984
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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