Magnetocaloric Effect and Magnetic Properties of Exciton Polaron in Monolayers Transition Metal Dichalcogenides Quantum Well

The magnetocaloric Effect (MCE) and magnetic properties of exciton-polaron in transition metal dichalcogenides quantum well was investigated. Using the Lee Low Pines method and an approximate diagonalization of exciton-phonon operators is achieved to investigate the ground and first excited states energies. Moreover, the partition function has been calculated using the grand canonical ensemble. Then, the entropy change well known as MCE, the magnetic susceptibility and the magnetization have been derived. Our results reveal that there is competition between thermal, magnetic field and quantum well contribution on the MCE, the magnetization and magnetic susceptibility. Dependent of the range of those parameters, this competition can exhibit interesting behavior such as high conventional magnetocaloric effect and local paramagnetism. We also found that magnetic field significantly affect the magnetic moment alignment and yield to statistical redistribution and reorganization of different states, moreover magnetic field drastically reduces disorder in the system. Likewise, results demonstrated that transition metal dichalcogenide materials offer several advantages such as magnetic stability, energetic robustness, gradual thermal control, predictable response, and a magnetocaloric effect exploitable over a wide temperature range due to its robustness and strong confinement. Tungsten disulfide (WS 2 ) material is more robust and sensitive whereas molybdenum diselenide (MoSe 2 ) material is more stable. The results obtained in this study can be used on sensitive thermomagnetic sensors, refrigerators and in data storage.