nn0c00291_si_001.pdf (1.87 MB)
Enhanced Valley Zeeman Splitting in Fe-Doped Monolayer MoS2
journal contribution
posted on 2020-03-17, 19:05 authored by Qi Li, Xiaoxu Zhao, Longjiang Deng, Zhongtai Shi, Sheng Liu, Qilin Wei, Linbo Zhang, Yingchun Cheng, Li Zhang, Haipeng Lu, Weibo Gao, Wei Huang, Cheng-Wei Qiu, Gang Xiang, Stephen John Pennycook, Qihua Xiong, Kian Ping Loh, Bo PengThe
“Zeeman effect” offers unique opportunities for
magnetic manipulation of the spin degree of freedom (DOF). Recently,
valley Zeeman splitting, referring to the lifting of valley degeneracy,
has been demonstrated in two-dimensional transition metal dichalcogenides
(TMDs) at liquid helium temperature. However, to realize the practical
applications of valley pseudospins, the valley DOF must be controllable
by a magnetic field at room temperature, which remains a significant
challenge. Magnetic doping in TMDs can enhance the Zeeman splitting;
however, to achieve this experimentally is not easy. Here, we report
unambiguous magnetic manipulation of valley Zeeman splitting at 300
K (geff = −6.4) and 10 K (geff = −11) in a CVD-grown Fe-doped MoS2 monolayer; the effective Landé geff factor can be tuned to −20.7 by increasing the Fe
dopant concentration, which represents an approximately 5-fold enhancement
as compared to undoped MoS2. Our measurements and calculations
reveal that the enhanced splitting and geff factors are due to the Heisenberg exchange interaction of the localized
magnetic moments (Fe 3d electrons) with MoS2 through the
d-orbital hybridization.