Spin and valley-dependent electron transport through arrays of ferromagnet on monolayer MoS₂

We theoretically study ballistic transport of Dirac fermions in MoS₂ junction through arrays of barriers, of width [Formula: see text], in the presence of a tunable potential of height [Formula: see text] and an exchange field [Formula: see text]. The charge conductance as functions of [Formula: see text] and [Formula: see text], exhibits more conspicuous and sharpened oscillation as the number of barriers increase, due to the contribution of evanescent modes near the edges of the extremum conductance which are exponentially suppressed or enhanced. Furthermore, we found the valley-resolved conductance exhibits a similar oscillating behavior as the charge conductance for multiple barriers, but with inverse oscillatory phases for [Formula: see text] and [Formula: see text], accordingly, a high-efficiency fully valley polarized device is proposed in our system. Also, a perfect 100% spin polarized conductance is observed for 4 barriers and the polarized direction can be switched by changing the direction of exchange field. These findings not only benefit understanding of basic physics in monolayers MoS₂, but also provide us a new way to generate a pure and high-efficiency spintronics and valleytronics.