Junho Choi1,Christopher Lane1,Jian-Xin Zhu1,Scott Crooker1
Los Alamos National Laboratory1
Junho Choi1,Christopher Lane1,Jian-Xin Zhu1,Scott Crooker1
Los Alamos National Laboratory1
2D van der Waals heterostructures comprising ferromagnetic and semiconductor materials represent a unique platform to explore the magnetic exchange interactions that can introduce an effective magnetism in non-magnetic semiconducting layers. These interfacial magnetic proximity effects include electronic wavefunction overlap, spin-dependent charge transfer, and band hybridization. Here, in MoSe<sub>2</sub>/CrBr<sub>3</sub> heterostructures, we employ magnetic circular dichroism (MCD) spectroscopy to observe valley Zeeman splitting of the monolayer MoSe<sub>2</sub> excitonic resonances due to magnetic proximity effects from the underlying CrBr<sub>3</sub>. The temperature and external magnetic field dependent measurements allow us to determine the characteristic of exchange interaction. The effective exchange field, studied at both the A- and B-exciton resonances in MoSe<sub>2</sub>, is on the order of a few tesla. Imaging experiments reveal the presence of magnetic domains in the ferromagnetic CrBr<sub>3</sub> layer.