Tunable chiral magneto-transport through band structure engineering in magnetic topological insulators Mn(Bi<sub>1-<i>x</i></sub>Sb<i><sub>x</sub></i>)<sub>2</sub>Te<sub>4</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 40378210.
- Also identified by DOI 10.1126/sciadv.adt6084 and PMC identifier 12083519.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Berry curvature and spin texture are representative tuning parameters that govern spin-orbit coupling-related physics and are also the foundation for future device applications. Here, we investigate the impact of the Sb-to-Bi ratio on shaping the electronic band structure and its correlated first- and second-harmonic magneto-transport signals in the intrinsic magnetic topological insulator Mn(Bi<sub>1-<i>x</i></sub>Sb<i><sub>x</sub></i>)<sub>2</sub>Te<sub>4</sub>. First-principles calculations reveal that the introduction of Sb not only triggers a topological phase transition but also changes the integral of the Berry curvature at the shifted Fermi level, which leads to the reversal of the anomalous Hall resistance polarity for Sb fractions <i>x</i> > 0.67. Moreover, it also induces the opposite spin splitting of the valence bands compared to the Sb-free host, and the resulting clockwise/counterclockwise spin chirality gives rise to a tunable unidirectional second-harmonic anomalous Hall response. Our findings pave the way for constructing chiral spin-orbitronic devices through band structure engineering.