Giant Anomalous Hall Effect due to Double-Degenerate Quasiflat Bands

Wei Jiang, Duarte J.P. De Sousa, Jian Ping Wang, Tony Low

Research output: Contribution to journalArticlepeer-review

Abstract

We propose a novel approach to achieve a giant anomalous Hall effect (AHE) in materials with flat bands (FBs). FBs are accompanied by small electronic bandwidths, which consequently increases the momentum separation (K) within pair of Weyl points and, thus, the integrated Berry curvature. Starting from a simple model with a single pair of Weyl nodes, we demonstrated the increase of K and the AHE by decreasing the bandwidth. It is further expanded to a realistic pyrochlore lattice model with characteristic double-degenerated FBs, where we discovered a giant AHE while maximizing the K with nearly vanishing band dispersion of FBs. We identify that such a model system can be realized and modulated through strain engineering in both pyrochlore and spinel compounds based on first-principles calculations, validating our theoretical model and providing a feasible platform for experimental exploration.

Original languageEnglish (US)
Article number106601
JournalPhysical review letters
Volume126
Issue number10
DOIs
StatePublished - Mar 10 2021

Bibliographical note

Funding Information:
This project is supported by SMART, one of seven centers of nCORE, a Semiconductor Research Corporation program, sponsored by National Institute of Standards and Technology (NIST). We acknowledge the MSI in the University of Minnesota for providing the computational resources.

Publisher Copyright:
© 2021 American Physical Society.

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