Optical absorption by Dirac excitons in single-layer transition-metal dichalcogenides
نویسندگان
چکیده
We develop an analytically solvable model able to qualitatively explain nonhydrogenicexciton spectra observed recently in two-dimensional (20) semiconducting transition-metal dichalcogenides. Our exciton Hamiltonian explicitly includes additional angular momentum associated with the pseudospin degree of freedom unavoidable in 20 semiconducting materials with honeycomb structure. We claim that this is the key ingredient for understanding the nonhydrogenic exciton spectra that was missing so far.
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