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Abstract Topological insulators (TI) and magnetic topological insulators (MTI) can apply highly efficient spin‐orbit torque (SOT) and manipulate the magnetization with their unique topological surface states (TSS) with ultrahigh efficiency. Here, efficient SOT switching of a hard MTI, V‐doped (Bi,Sb)2Te3(VBST), with a large coercive field that can prevent the influence of an external magnetic field, is demonstrated. A giant switched anomalous Hall resistance of 9.2 kΩ is realized, among the largest of all SOT systems, which makes the Hall channel a good readout and eliminates the need to fabricate complicated magnetic tunnel junction (MTJ) structures. The SOT switching current density can be reduced to 2.8 × 105 A cm−2, indicating its high efficiency. Moreover, as the Fermi level is moved away from the Dirac point by both gate and composition tuning, VBST exhibits a transition from edge‐state‐mediated to surface‐state‐mediated transport, thus enhancing the SOT effective field to (1.56 ± 0.12) × 10−6 T A−1 cm2and the interfacial charge‐to‐spin conversion efficiency to 3.9 ± 0.3 nm−1. The findings establish VBST as an extraordinary candidate for energy‐efficient magnetic memory devices.
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This content will become publicly available on February 1, 2026
Bonding Interactions Can Drive Topological Phase Transitions in a Zintl Antiferromagnetic Insulator
Abstract While ∼30% of materials are reported to be topological, topological insulators are rare. Magnetic topological insulators (MTI) are even harder to find. Identifying crystallographic features that can host the coexistence of a topological insulating phase with magnetic order is vital for finding intrinsic MTI materials. Thus far, most materials that are investigated for the determination of an MTI are some combination of known topological insulators with a magnetic ion such as MnBi2Te4. Motivated by the recent success of EuIn2As2, the role of chemical pressure on topologically trivial insulator is investigated, Eu5In2Sb6via Ga substitution. Eu5Ga2Sb6is predicted to be topological but is synthetically difficult to stabilize. The intermediate compositions between Eu5In2Sb6and Eu5Ga2Sb6are observed through theoretical works to explore a topological phase transition and band inversion mechanism. The band inversion mechanism is attributed to changes in Eu–Sb hybridization as Ga is substituted for In due to chemical pressure. Eu5In4/3Ga2/3Sb6is also synthesized, the highest Ga concentration in Eu5In2‐xGaxSb6, and report the thermodynamic, magnetic, transport, and Hall properties. Overall, the work paints a picture of a possible MTI via band engineering and explains why Eu‐based Zintl compounds are suitable for the co‐existence of magnetism and topology.
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- PAR ID:
- 10579897
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 35
- Issue:
- 8
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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