Magnetic barrier and temperature effects on optical and dynamic properties of exciton-polaron in monolayers transition metal dichalcogenides

Abstract

We theoretically investigate the properties of exciton-polaron moving through a magnetic barrier in monolayers (1Ls) transition metal dichalcogenides (TMDs): MoS 2 , WS 2 , MoSe 2 , and WSe 2 . We find that the exciton-polaron has the highest ground state energy in WS 2 and the lowest one in MoSe 2 . It is seen that the magnetic barrier stabilizes the excitonic polaron system subjected to thermal perturbation. We demonstrate that the entropy of the system is very sensitive to the type of monolayers TMDs, the length scale of the barrier, the temperature. We observe that the higher the magnetic length, the greater the disorder in exciton-polaron system and the highest entropy is in MoSe 2 . Also, the mobility and the lifetime of exciton-polaron decrease with the enhancement of the magnetic length. We observe the highest mobility and lifetime in WS 2 . Moreover, We show that the optical absorption appears when the photon energy is more than twice phonon energy and the absorption coefficient is higher when the incident photon induces an in plane field. MoS 2 presents the highest amplitude of optical absorption. • Amount the selected TMD the MoS 2 presents the highest amplitude of optical absorption. The exciton-polaron has the highest ground state energy in WS 2 and the lowest one in MoSe 2 . • The magnetic barrier stabilizes the exciton-polaron system subjected to thermal perturbation. • The entropy of the system is very sensitive to the type of monolayers TMDs, the length scale of the barrier and the temperature. • The higher the magnetic length, the greater the disorder in exciton-polaron system and the highest entropy is in MoSe 2 . • The mobility and the lifetime of exciton-polaron decrease with the enhancement of the magnetic length,these two parameters are stronger in WS 2. .