Observing and Suppressing Metallization in MoS₂ for Near-Ideal Spin Filtering

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spintronics

Background:

• Two-dimensional (2D) transition-metal dichalcogenides (TMDCs) show promise for spin filtering due to their band alignments when interfaced with ferromagnets.
• Interfacial hybridization in materials like MoS2 leads to metallic states, hindering spin transport and limiting device performance below theoretical predictions.

Purpose of the Study:

• Investigate metallization at the Cobalt/Molybdenum disulfide (Co/MoS2) interface.
• Develop a method to mitigate the negative effects of metallization on spin transport in 2D TMDC-based spintronic devices.

Main Methods:

• Utilized a contamination-free fabrication process to create Co/MoS2 interfaces.
• Conducted magneto-transport measurements and theoretical analysis.
• Performed temperature-dependent characterization to distinguish transport regimes.

Main Results:

• Observed clear evidence of hybridization at the Co/MoS2 interface, which enhanced magnetic anisotropy.
• Metallic wave functions were found to extend into the MoS2 layer, suppressing its spin-filtering capability.
• Restored spin-filtering ability by separating MoS2 with two atomic layers, achieving a record tunneling magnetoresistance (TMR) of -170.2%.

Conclusions:

• The study establishes a viable strategy for fabricating high-performance 2D spintronic devices.
• The findings pave the way for scalable applications in MRAM, spin logic, and magnetic sensing.
• The achieved TMR is consistent with simulations of ideal minority spin filtering, validating the proposed method.