Toward Two-Dimensional van der Waals Magnon Transport Devices: WTe₂ Electrodes for Efficient Magnon Spin Injection...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Spintronics

Background:

• Two-dimensional (2D) materials are crucial for advanced magnon transport devices.
• Efficient injection and detection of magnon spins remain a significant challenge.
• Conventional electrodes lack dual functionality for in-plane and out-of-plane spin polarization without magnetic fields.

Purpose of the Study:

• To investigate WTe2 as a 2D material for efficient magnon spin injection and detection.
• To explore the dual functionality of WTe2 in handling both in-plane and out-of-plane magnon spin polarizations.
• To compare the spin-charge conversion efficiency of WTe2 with conventional electrodes like platinum.

Main Methods:

• Fabrication of a hybrid nonlocal device using WTe2 and CrPS4 (a 2D antiferromagnet).
• Utilized WTe2 as both spin injector and detector contacts.
• Employed conventional platinum contacts for comparison in the same device geometry.

Main Results:

• WTe2 demonstrates efficient injection and detection of in-plane polarized spins via the spin Hall effect.
• WTe2 enables detection of out-of-plane polarized magnon spins through unconventional charge-to-spin conversion.
• WTe2 exhibits approximately 0.45 and 1.7 times higher charge-to-spin conversion efficiency for in- and out-of-plane spins, respectively, compared to platinum's in-plane efficiency.

Conclusions:

• WTe2 is a versatile 2D material capable of efficient magnon spin injection and detection.
• Its unique ability to handle both in-plane and out-of-plane spin polarizations is critical for future 2D spintronic devices.
• WTe2 offers superior spin-charge conversion efficiency, paving the way for advanced spintronic applications.