Magnetic proximity controlled Rashba and valley splittings in monolayer Janus ZrNX/VTe2 (X = Br, I) heterostructure

Due to the symmetry breaking, Janus two-dimensional materials possess novel electronic properties such as energy valley and spin polarization. In this research, we predicted the Zeeman-type spin splitting and Rashba splitting of monolayer Janus ZrNX (X = Br, I). The Rashba spin splitting and valley splitting can be greatly tuned by the magnetic proximity effect of monolayer H–VTe2, which are dependent on the stacking configurations. There is strong interlayer coupling between Janus ZrNX and VTe2, leading to a sizable valley splitting of 87 meV. The valley splitting can be significantly enlarged by the vertical compression strain, because of the increases of effective Zeeman field and in-plane orbital component. In addition, a helical gap is opened and the dispersion relation of Rashba spin-orbit coupling is obviously modified by in-plane biaxial strain. The Rashba constant and helical gap increase with the in-plane tensile strain, which leads from the larger potential energy difference and magnetic moment of surface V atoms. The greatly tunable spin/valley splittings in ZrNBr/VTe2 heterostructure are of some signification for the development of spintronics/valleytronics and the realization of new functional devices.