Quantum mechanics

Magnetic field

Quantization (signal processing)

Quantum spin Hall effect

Ferromagnetism

Superlattice

Computer science

Berry connection and curvature

Quantum anomalous Hall effect

Physics

Mathematics

Topological insulator

Fermi energy

Geometric phase

Condensed matter physics

Combinatorics

Quantum Hall effect

Electron

Topology (electrical circuits)

Hall effect

Computer vision

Landau quantization

Nature Physics

The quantum anomalous Hall effect1,2 is a fundamental transport response of a topological insulator in zero magnetic field. Its physical origin is a result of an intrinsically inverted electronic band structure and ferromagnetism3, and its most important manifestation is the dissipationless flow of chiral charge currents at the edges of the system4, a property that has the potential to transform future quantum electronics5,6. Here, we report a Berry-curvature-driven4,7 anomalous Hall regime at temperatures of several Kelvin in the magnetic topological bulk crystals in which Mn ions self-organize into a period-ordered MnBi2Te4/Bi2Te3 superlattice. Robust ferromagnetism of the MnBi2Te4 monolayers opens a surface gap8–10, and when the Fermi level is tuned to be within this gap, the anomalous Hall conductance reaches an e2/h quantization plateau, which is a clear indication of chiral transport through the edge states. The quantization in this regime is not obstructed by the bulk conduction channels and therefore should be present in a broad family of topological magnets. A three-dimensional topological magnetic superlattice structure exhibits the quantum anomalous Hall effect when the Fermi energy is tuned into the correct energy window.

High-temperature quantum anomalous Hall regime in a MnBi2Te4/Bi2Te3 superlattice