Importance of the semimetallic state for the quantum Hall effect in HfTe${}_5$

Abstract

At ambient pressure, HfTe${}_5$ is a material at the boundary between a weak and a strong topological phase, which can be tuned by changes in its crystalline structure or by the application of high magnetic fields. It exhibits a Lifshitz transition upon cooling, and three-dimensional (3D) quantum Hall effect (QHE) plateaus can be observed at low temperatures. Here, we have investigated the electrical transport properties of HfTe${}_5$ under hydrostatic pressure up to 3 GPa. We find a pressure-induced crossover from a semimetallic phase at low pressures to an insulating phase at about 1.5 GPa. Our data suggest the presence of a pressure-induced Lifshitz transition at low temperatures within the insulating phase around 2 GPa. The quasi-3D QHE is confined to the low-pressure region in the semimetallic phase. This reveals the importance of the semimetallic groundstate for the emergence of the QHE in HfTe${}_5$ and thus favors a scenario based on a low carrier density metal in the quantum limit for the observed signatures of the quasi-quantized 3D QHE.

References in corpus (7)

• Quantum Hall effect in a bulk antiferromagnet EuMnBi${}_2$ with magnetically confined two-dimensional Dirac fermions
• Topological quantum materials from the viewpoint of chemistry
• Origin of the quasi-quantized Hall effect in ZrTe5
• Bulk quantum Hall effect of spin-valley-coupled Dirac fermions in a polar antiferromagnet BaMnSb${}_2$
• Topological Lifshitz transition and one-dimensional Weyl mode in HfTe5
• Quantum-Hall physics and three dimensions
• Engineering a pure Dirac regime in ZrTe${}_5$

Cited by in corpus (2)

• Pressure induced electronic band evolution and observation of superconductivity in the Dirac semimetal ZrTe5
• Effect of pressure on the transport properties and thermoelectric performance of Dirac semimetal ZrTe5