Spin transport in antiferromagnet/Weyl semimetal heterostructures
ORAL
Abstract
The type-II Weyl semimetal TaIrTe₄, characterized by its broken mirror symmetries, can generate spin polarizations with both in-plane and out-of-plane components depending on the current direction. While numerous studies on TaIrTe₄/ferromagnet heterostructures have revealed a variety of interesting phenomena, including field-free deterministic magnetization switching [1–3], spin-torque resonance [4], and proximity-induced anomalous Hall effects [5], the effects of spin currents generated by TaIrTe₄ on antiferromagnets has not yet been explored.
In this work, we fabricate α-Fe₂O₃/ TaIrTe₄ heterostructures by mechanically exfoliating TaIrTe₄ flakes onto pulsed-laser-deposited, atomically flat, hematite thin films(~100 nm) epitaxially grown on Al2O3(0001) substrates. All exfoliation steps are performed inside a glovebox under inert atmosphere to prevent oxidation and maintain a pristine interface. The flakes are subsequently patterned into a waffle-like geometry via electron-beam lithography and reactive ion etching, enabling simultaneous monitoring of both longitudinal and transverse transport signals for current flowing in either a- or b- direction.
Clear spin Hall magnetoresistance (SMR) responses are observed under both in-plane and out-of-plane magnetic field rotation measurements. The in-plane rotation signals in both longitudinal and transverse channels reveal the SMR origin with in-plane spin polarization, while the out-of-plane rotation signals suggest the presence of out-of-plane spin polarization. These results highlight type-II Weyl semimetals as a promising platform for antiferromagnetic spintronic applications.
[1] D. Li et al., Phys. Rev. B 110, 035423 (2024).
[2] Y. Liu et al., Nat Electron 6, 732 (2023).
[3] Y. Zhang et al., Advanced Materials 36, 2406464 (2024).
[4] L. Bainsla et al., Nat Commun 15, 4649 (2024).
[5] I.-H. Kao et al., (2025).
In this work, we fabricate α-Fe₂O₃/ TaIrTe₄ heterostructures by mechanically exfoliating TaIrTe₄ flakes onto pulsed-laser-deposited, atomically flat, hematite thin films(~100 nm) epitaxially grown on Al2O3(0001) substrates. All exfoliation steps are performed inside a glovebox under inert atmosphere to prevent oxidation and maintain a pristine interface. The flakes are subsequently patterned into a waffle-like geometry via electron-beam lithography and reactive ion etching, enabling simultaneous monitoring of both longitudinal and transverse transport signals for current flowing in either a- or b- direction.
Clear spin Hall magnetoresistance (SMR) responses are observed under both in-plane and out-of-plane magnetic field rotation measurements. The in-plane rotation signals in both longitudinal and transverse channels reveal the SMR origin with in-plane spin polarization, while the out-of-plane rotation signals suggest the presence of out-of-plane spin polarization. These results highlight type-II Weyl semimetals as a promising platform for antiferromagnetic spintronic applications.
[1] D. Li et al., Phys. Rev. B 110, 035423 (2024).
[2] Y. Liu et al., Nat Electron 6, 732 (2023).
[3] Y. Zhang et al., Advanced Materials 36, 2406464 (2024).
[4] L. Bainsla et al., Nat Commun 15, 4649 (2024).
[5] I.-H. Kao et al., (2025).
*This research was supported in part by DOE award #DE-FG02-07ER46351, #DE-SC0021117, and by funds from the UC National Laboratory Fees Research Program of the University of California, Grant Number L25CR9003.
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Presenters
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Jia-Mou Chen
- University of California, Riverside