Mechanical Tuning of Giant Magnetoresistance and Spin Filtering in Manganese Diporphyrin‐Based Molecular Junction

Abstract

AbstractBy employing spin‐polarized density functional theory (DFT) combined with non‐equilibrium Green's function technique (NEGF), we have investigated the spin transport properties of a series of manganese diporphyrins (MnDPs) with different torsion angle (θ=0°, 10°, 20°, 30°, 40°, 50°, 60°). It is found that the spin transport properties of molecular junctions can be modulated by mechanical tuning of different dihedral angle. In addition, the molecular junctions have characterized Giant magnetoresistance (GMR), spin filtering effect (SFE) and negative differential resistance (NDR). More interestingly, our results show that the MR could reach over 14000 % at low bias voltage, and nearly perfect spin filtering efficiency can be obtained when the torsion angle θ=20°. The numerical analysis reveals that the matching of PDOS for two parts of MnDP molecule is the physical mechanism which is causing the appearance of GMR in the low bias voltage. Our findings might be useful for the application of MnDP‐based molecular devices.