2023, Enhanced Valley Polarization in WSe2/YIG Heterostructures via Interfacial Magnetic Exchange Effect, Nano Research
2023, Enhanced Valley Polarization in WSe2/YIG Heterostructures via Interfacial Magnetic Exchange Effect, Nano Research
Abstract:
Exploiting the valley's degrees of freedom as information carriers provide new opportunities for the development of Valleytronics. Monolayer transition metal dichalcogenides(TMDs) with broken space-inversion symmetry exhibit emerging valley pseudospins, making them ideal platforms for studying valley electronics. However, intervalley scattering of different energy valleys limits the degree of valley polarization achievable. Here, we constructed WSe2/YIG heterostructures and demonstrated that the interfacial magnetic exchange effect on the YIG magnetic substrate can enhance valley polarization by up to 63%, significantly higher than that of a monolayer WSe2 on SiO2/Si (11%). Additionally, multiple sharp exciton peaks appear in the WSe2/YIG heterostructures due to the strong magnetic proximity effect at the magnetic-substrate interface that enhances exciton emission efficiency. Moreover, under the effect of the external magnetic field, the magnetic direction of the magnetic substrate enhances valley polarization, further demonstrating that the magnetic proximity effect regulates valley polarization. Our results provide a new way to regulate valley polarization and demonstrate the promising application of magnetic heterojunctions in magneto-optoelectronics.
Keywords: WSe2/YIG Heterostructures, Valley Polarization, Interfacial Magnetic Exchange Effect, Magnetic proximity effect.
Link:https://link.springer.com/article/10.1007/s12274-023-5865-x
