Giant Magnetoresistance in Transition Metal Dichalcogenide Monolayers
Frank Hagelberg
East Tennessee State University, Department of Physics and Astronomy, Johnson City, TN, 37614
Transition metal dichalcogenides (TMDCs) are semiconductors that form layered structures. TMDC bulk crystals are stacks of two-dimensional MX2 layers where M stands for a transition metal atom (such as Mo or W) and X for a chalcogen atom (such as S, Se or Te). TMDC monolayers provide us with materials of atomic scale thickness that combine an electronic band gap with strong spin–orbit coupling, and have favorable mechanical and optical properties. In consequence, they are interesting for applications in nanoelectronics and nanospintronics.
In this contribution, we consider TMCD monolayers of the zigzag type. Using density functional theory (DFT) in conjunction with a non-equilibrium Green’s Function (NEGF) approach, we discuss these species in terms of their magnetoresitive properties. Focusing on the species MoS2 and WS2, and exploring the bias regime up to 10 mV, we found very marked conductivity differences between the two competing magnetic configurations, i.e. parallel and anti-parallel orientation between the spins located at the ends of the TMDC structures. For the magnetoresistance ratio, we obtained a maximum value of 13,500 percent for MoS2. This suggests that an MoS2-based zigzag monolayer might serve as spin valve in spintronics networks.