The role of electron-phonon interactions on the coherence lifetime of monolayer transition metal dichalcogenides

[摘要] We investigate the excitonic dephasing of transition metal dichalcogenides, namely MoS2, MoSe2and WSe2atomic monolayer thick and bulk crystals, in order to understand the factors that determine the optical coherence in these materials. Coherent nonlinear optical spectroscopy, temperature dependent absorption combined with theoretical calculations of the phonon spectra, reveal the important role electron-phonon interactions plat in dephasing process. The temperature dependence of the electronic band gap and the excitonic linewidth combined with 'ab initio' calculations of the phonon energies and the phonon density of state reveal strong interaction with the E' and E" phonon modes.

[发布机构] Department of Physics, University of South Florida, 4202 East Fowler Ave., Tampa; FL; 33620, United States^1;Department of Physics, Pennsylvania State University, University Park; PA; 16802, United States^2;Physics Department, West Virginia University, Morgantown; WV; 26506-6315, United States^3;Department of Physics, University of Alabama at Birmingham, Birmingham; AL; 35294, United States^4

[关键词] Electronic band gaps;Nonlinear optical spectroscopy;Phonon density of state;Strong interaction;Temperature dependence;Temperature dependent;Theoretical calculations;Transition metal dichalcogenides