Enhancing Tunneling Current in Cr<i>X</i>₃ (<i>X</i> = Cl, I) Junctions using Transition Metal Dichalcogenides

Over the past few years, the fabrication of graphene/CrX₃ (X = Cl, Br, I) magnetic tunnel junction (MTJ) devices has been achieved. While graphene/CrI₃ MTJs have demonstrated large tunneling magnetoresistances (TMR), the conductance in these devices is disproportionately low compared to conventional devices due to the vanishing graphene states near the Fermi level. In order to circumvent this limitation, transition metal dichalcogenides NbSe₂ and TaSe₂ stand as alternative readily-available electrodes. Here we use first principles calculations within the density functional theory and Landauer’s formalism of ballistic transport to characterize 2H-MSe₂ (M = Nb, Ta)/CrX₃ (X = Cl, I) based MTJs. We rationalize the obtained TMR values in terms of the properties of the junctions (e.g. electrode density of states, complex band structure, band alignments, junction thickness, etc.). While the TMR results are comparable to those found in graphene/CrX₃ heterostructures, we observe approximately two orders of magnitude larger conductance values, which facilitates experimental observations. The descriptions that account for the systems’ atomistic properties aid the rational design of future MTJs based on 2D materials.