Electric filed dependent valley polarization in 2D WSe <sub>2</sub> /CrGeTe <sub>3</sub> heterostructure
Brahim Marfoua, Jisang Hong
Abstract
Abstract Valleytronics in 2D transition metal dichalcogenides (TMDs) has received extensive interest as a promising field for information processing, storage, and logic operation applications. Here, we have investigated the electric field dependent valley polarization of 2D WSe 2 /CrGeTe 3 heterostructure. The WSe 2 /CrGeTe 3 system has an indirect band gap of 0.253 eV without spin–orbit coupling (SOC), and this is reduced to 21 meV with SOC. The WSe 2 /CrGeTe 3 system has a weak perpendicular magnetic anisotropy of 0.05 meV cell −1 , and the critical temperature is 38 K. The magnitude of the valley polarization is 3 meV without an electric field. For instance, we obtain the valley polarization of 9 meV if the electric field of 0.4 V Å −1 is applied from the CrGeTe 3 to the WSe 2 , but it becomes 0.5 meV if the electric field direction is reversed even at the same intensity. We have found that the charge redistribution happens depending on the electric field direction. So, we attribute this feature to the electric field dependent valley polarization of the 2D WSe 2 /CrGeTe 3 heterostructure.