Quantum Hall Effect and insulating behavior induced by magnetic field in ZrTe₅

The discovery of Dirac Materials (DM) and Topological Insulator (TI) provided a fascinating field in exploring the quantum dynamics of relativistic field theory in condensed matter systems. With a strong magnetic field, the state of DM could convert into other exotic phases like as Weyl fermions, Charge Density Wave, Spin Density Wave, Axion insulator, and excitonic insulator. In this work, we report the experimental observation of a quantum Hall effect in 3D Zirconium Penta-Telluride（ZrTe₅）within a small magnetic field B (<1.3T) regime. As further increasing magnetic field, the system has reached the quantum limit regime, beyond its lowest Landau Level. The magneto-resistance ρ_xx increases dramatically and display insulator behavior above certain critical magnetic field B_c. We suggest this metal-insulator transition (MIT) is more like relevant to the many-body interactions.