Quantitatively calculate the magnetoresistance and Hall effects of real materials from first principles methodology

Speaker

Quan Sheng Wu

Affiliation

Key Laboratory of Condensed Matter Theory and Computation, Institute of Physics, Chinese Academy of Sciences

When
Place

DIPC Seminar Room

Host

Bogdan A. Bernevig

This talk will introduce a method that combines first-principles calculations with semiclassical Boltzmann transport theory to quantitatively calculate the magnetoresistance (MR) and Hall effect in real materials including non-magnetic metals, semimetals, semiconductors, and magnetic materials. It discusses the unsaturated MR and anisotropic MR effects in both topologically trivial and topological materials, revealing the crucial roles of carrier compensation, open orbit mechanisms, and Fermi surface topology. The study shows that theoretical predictions are highly consistent with low-temperature experimental results in typical metals, semimetals, and Weyl semimetals, and also discovers that Kohler's rule applies to Hall resistivity, clarifying the proportional relationships and intrinsic 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 multicarrier dynamics and Fermi surface geometry. The introduced new method successfully explains the complex magnetoresistance and Hall effect behaviors in magnetic materials, aligning closely with experiments, highlighting the decisive role of Fermi surface shape and average scattering time on transport properties. We will also introduce a new interpretation of the peculiar behavior of the rho-T curves under magnetic fields. Our talk provides a new theoretical framework for understanding magnetotransport phenomena and opens new avenues 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, 035142 (2019).

2. Complex field-, temperature-, and angle-dependent Hall effects from intrinsic Fermi surface revealed by first-principles calculations, SN Zhang, Z Liu, H Pi, Z Fang, H Weng*, QS Wu*, Physical Review B 110, 205132 (2024)

3. Combined first-principles and Boltzmann transport theory methodology for studying magnetotransport in magnetic materials, Z Liu, S Zhang, Z Fang, H Weng*, Q Wu*, Physical Review Research 6, 043185 (2024)

4. First principles methodology for studying magnetotransport in narrow gap semiconductors with ZrTe5 example, Hanqi Pi, Shengnan Zhang*, Yang Xu, Zhong Fang, Hongming Weng* and Quansheng Wu*, npj Computational Materials 10, 276 (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/