MML Seminar - First-principle methodology for magnetoresistance and Hall effects

In this talk, we will introduce a method combining first-principles calculations with semiclassical Boltzmann transport theory to compute magnetoresistance and Hall effects in real materials. It will discuss the unsaturated magnetoresistance effects in both topologically trivial and topological materials, highlighting the crucial roles of carrier compensation, open orbit mechanisms, and Fermi surface topology. Studies have shown that theoretical predictions highly align with the low-temperature experimental results of typical metals, semimetals, and Weyl semimetals, and also discovered that Kohler's rule applies to Hall resistivity, clarifying the proportional relationship and inherent laws between ordinary Hall effect and anomalous Hall effect. For the anomalous resistance peaks and Hall resistivity sign reversals in narrow-gap semiconductors, we propose a unified explanation based on multi-carrier dynamics and Fermi surface geometry. The introduced new method successfully explains the complex behaviors of magnetoresistance and Hall effects in magnetic materials, highly consistent with experimental results, and highlights the decisive role of Fermi surface shape and mean scattering time on transport properties. Additionally, we will introduce a new interpretation of the peculiar behavior of rho-T curves under magnetic fields. Our research provides a new theoretical framework for understanding magnetic transport phenomena and opens new pathways for material classification and characteristic characterization.

References：

1. Magnetoresistance from Fermi surface topology, SN Zhang, QS Wu*, Y Liu, OV Yazyev*, Physical Review B 99 (3), 035142 (2019).

2. New perspectives of Hall effects from first-principles calculations, SN Zhang, H Pi, Z Fang, H Weng*, QS Wu*, arXiv:2401.151503 (2024)

3. First-principles Methodology for studying magnetotransport in magnetic materials Z Liu, S Zhang, Z Fang, H Weng*, QS Wu*, arXiv:2401.15146 (2024)

4. First-principles methodology for studying magnetotransport in narrow-gap semiconductors: an application to Zirconium Pentatelluride ZrTe5, H Pi, S Zhang*, Y Xu, Z Fang, H Weng*, QS Wu*, arXiv:2401.15151 (2024)

5. The inadequacy of the ρ-T curve for phase transitions in the presence of magnetic fields, Shengnan Zhang, Zhong Fang, Hongming Weng, Quansheng Wu*, arXiv:2405.15981 (2024)

6. WannierTools, https://www.wanniertools.org/