Quantum mechanics

Electrical resistivity and conductivity

Fermi level

Magnetic field

Quantization (signal processing)

Magnetization

Computer science

Mathematical optimization

Hamiltonian (control theory)

Physics

Fermi surface

Mathematics

Superconductivity

Condensed matter physics

Quantum Hall effect

Electron

Hall effect

Computer vision

Nature Communications

The quantum Hall effect (QHE) is traditionally considered a purely two-dimensional (2D) phenomenon. Recently, a three-dimensional (3D) version of the QHE has been reported in the Dirac semimetal ZrTe5. It was proposed to arise from a magnetic-field-driven Fermi surface instability, transforming the original 3D electron system into a stack of 2D sheets. Here, we report thermodynamic, thermoelectric and charge transport measurements on ZrTe5 in the quantum Hall regime. The measured thermodynamic properties: magnetization and ultrasound propagation, show no signatures of a Fermi surface instability, consistent with in-field single crystal X-ray diffraction. Instead, a direct comparison of the experimental data with linear response calculations based on an effective 3D Dirac Hamiltonian suggests that the quasi-quantization of the observed Hall response is an intrinsic property of the 3D electronic structure. Our findings render the Hall effect in ZrTe5 a truly 3D counterpart of the QHE in 2D systems.

Origin of the quasi-quantized Hall effect in ZrTe5