New website: weichichiu.com

Magnetic Weyl & Spin-Orbit Physics

Figure 3 from the CeAlSi paper: band structure, density of states, Weyl nodes, magnetic tuning, and anomalous Hall conductivity.

Source: Fig. 3, H.-Y. Yang et al., Physical Review B 103, 115143 (2021).

Noncollinear Ferromagnetic Weyl Semimetal with Anisotropic Anomalous Hall Effect

Hung-Yu Yang, Bahadur Singh, Jonathan Gaudet, Baozhu Lu, Cheng-Yi Huang, Wei-Chi Chiu, et al.

Physical Review B 103, 115143 (2021).

CeAlSi establishes a distinct class of noncollinear magnetic Weyl semimetals in which magnetization direction tunes the Weyl nodes and Berry-curvature-driven response. By combining first-principles calculations with neutron scattering and transport measurements, we connected the unusual anisotropic anomalous Hall response and loop Hall effect to the proximity of the Fermi level to the Weyl nodes and to magnetic-domain physics.

Source: Fig. 3, H.-Y. Yang et al., APL Materials 8, 011111 (2020).

Transition from Intrinsic to Extrinsic Anomalous Hall Effect in PrAlGe1−xSix

Hung-Yu Yang, Bahadur Singh, Baozhu Lu, Cheng-Yi Huang, Faranak Bahrami, Wei-Chi Chiu, et al.

APL Materials 8, 011111 (2020).

Chemical substitution in PrAlGe1−xSix provides a controlled way to tune anomalous Hall transport without destroying the underlying Weyl-node structure. First-principles calculations and Hall-scaling analyses reveal a universal intrinsic contribution for x < 0.5 and an extrinsic regime for x > 0.5, demonstrating how band filling and scattering mechanisms compete in ferromagnetic Weyl semimetals.

Figure 4 from the TbPtBi paper: spin-resolved bands, spin-orbit-induced anticrossings, Berry curvature, Weyl nodes, and anomalous Hall conductivity.

Source: Fig. 4, Y. Zhu et al., Physical Review B 101, 161105(R) (2020).

Exceptionally Large Anomalous Hall Effect from Spin-Split Band Anticrossings in TbPtBi

Yanglin Zhu, Bahadur Singh, Yu Wang, Cheng-Yi Huang, Wei-Chi Chiu, et al.

Physical Review B 101, 161105(R) (2020).

TbPtBi exhibits an exceptionally large anomalous Hall effect in its canted antiferromagnetic state, with an anomalous Hall angle reaching approximately 0.68–0.76. First-principles calculations show that the response is not dominated by Weyl points; instead, it originates from intense Berry curvature generated by anticrossings of spin-split bands near the Fermi level.

Source: Fig. 2, T. Hakioglu et al., Physical Review B 108, 155103 (2023).

Nonorthogonal Spin–Momentum Locking

Tugrul Hakioglu†, Wei-Chi Chiu†, Robert S. Markiewicz, Bahadur Singh, and Arun Bansil

Physical Review B 108, 155103 (2023). † Co-first authors.

We showed that spin–orbit scattering from dilute spinless impurities can rotate the spin texture away from the conventional perpendicular relation between spin and momentum. Above a characteristic coupling threshold, the resulting deflection angle provides an experimentally accessible signature in spin- and angle-resolved photoemission and affects spin-to-charge conversion and quasiparticle-interference measurements.

Page updated

Google Sites

Report abuse