Spin-Hall magnetoresistance in α-Fe₂O₃/TaIrTe₄ heterostructures

Low crystal symmetry in type-II Weyl semimetals, such as TaIrTe₄, makes them a distinct spin source with unconventional properties. When a charge current flows along the broken mirror symmetry axis in TaIrTe₄, it generates out-of-plane spin polarization, uniquely suited for spintronics applications. Although field-free switching in TaIrTe₄/ferromagnet heterostructure has been demonstrated, the spin injection into antiferromagnetic systems remains unexplored. Here, we exfoliate TaIrTe₄ onto antiferromagnetic insulator hematite (α-Fe₂O₃) thin films grown by pulsed laser deposition (PLD). The exfoliation process is performed in a glovebox to protect the TaIrTe₄/α-Fe₂O₃ interface from contamination and degradation. Using electron beam lithography, we pattern the samples into both circular disks and standard Hall bars. After sputtering Pt as the electrodes, we then etch away excess TaIrTe₄. In contrast to the pure TaIrTe₄reference sample, the intimate contact with hematite imprints magnetic order information onto the angular dependence of the spin-Hall magnetoresistance of α-Fe₂O₃/TaIrTe₄ heterostructure. Our findings open up new possibilities for antiferromagnetic spintronic applications.