High temperature, gate-free quantum anomalous Hall effect with an active capping layer

Abstract

Quantum anomalous Hall effect (QAHE) was discovered a decade ago, but is still not utilized beyond a handful of research groups, due to numerous limitations such as extremely low temperature, electric field-effect gating requirement, small sample sizes and environmental aging effect. Here, we present a robust platform that provides effective solutions to these problems. Specifically, on this platform, we observe QAH signatures at record high temperatures, with the Hall conductance of 1.00 e2/h at 2.0 K, 0.98 e2/h at 4.2 K, and 0.92 e2/h at 10 K, on centimeter-scale substrates, without electric-field-effect gating. The key ingredient is an active CrOx capping layer, which substantially boosts the ferromagnetism while suppressing environmental degradation. With this development, QAHE will now be accessible to much broader applications than before.

20 pages, 8 figures, Accepted for publication in Nano Letters, https://pubs.acs.org/doi/full/10.1021/acs.nanolett.3c01313

References in corpus (5)

• High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator
• Tailoring tricolor structure of magnetic topological insulator for robust axion insulator
• Large Anomalous Hall Effect in Topological Insulators with Proximitized Ferromagnetic Insulators
• Surface versus bulk state in topological insulator Bi2Se3 under environmental disorder
• Record-High Proximity-Induced Anomalous Hall Effect in (Bi${}_x$Sb${}_{1-x}$)2Te${}_3$ Thin Film Grown on CrGeTe${}_3$ Substrate

Cited by in corpus (6)

• Atomic-Layer-Controlled Magnetic Orders in MnBi2Te4-Bi2Te3 Topological Heterostructures
• Single-layer magnet phase in intrinsic magnetic topological insulators, $[\mathrm{MnTe}][{\mathrm{Bi}}_2{\mathrm{Te}}_3{]}_{\mathrm{n}}$, far beyond the thermodynamic limit
• Effects of GaAs buffer layer on quantum anomalous Hall insulator Vy(BixSb1-x)2-yTe3
• Magneto-optical effects of an artificially-layered ferromagnetic topological insulator with T${}_C$ of 160 K
• Effects of GaAs Buffer Layer on Structural, Magnetic, and Transport Properties of Magnetic Topological Insulators Cr${}_y$(Bi${}_x$Sb${}_{1-x}$)${}_{2-y}$Te${}_3$ and V${}_y$(Bi${}_x$Sb${}_{1-x}$)${}_{2-y}$Te${}_3$ Films
• Quantum anomalous Hall effect in chiral semimetals