SurfaceScience21 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 96: Poster Session VII: Poster to Mini-Symposium: Frontiers of electronic-structure theory IV
O 96.6: Poster
Donnerstag, 4. März 2021, 10:30–12:30, P
gauge-covariant derivatives of the Berry curvature and orbital moment by Wannier interpolation — •Xiaoxiong Liu1, Miguel Ángel Herrera2, Stepan Tsirkin1, and Ivo Souza2 — 1Department of Physics, University of Zurich — 2Centro de Física de Materiales, Universidad del País Vasco
The momentum-space derivatives of the Berry curvature Ω and intrinsic orbital magnetic moment m of the Bloch states arise in multiple problems, such as the nonlinear anomalous Hall effect [1] and magneto-transport within the Boltzmann-equation formalism [2]. To study them from first principles, we developed a Wannier interpolation scheme for evaluating "generalized derivatives" of the non-Abelian Ω and m matrices for a group of bands of interest.
The generalized derivative does not involve couplings within the group, and preserves the gauge covariance of the Ω and m matrices. This formulation leads to robust *Fermi-sea* formulas for the Berry curvature dipole [1] and kinetic magnetoelectric effect tensor [2], which converge much faster with the density of the integration k-grid than the *Fermi-surface* formulas implemented earlier [3] in the Wannier90 code. The implementation is done in our newly-developed code WannierBerri [4]. We demonstrate the method with ab initio calculations on real materials, as well as tight-binding toy models.
[1] Sodemann et al, PRL 115 (2015): 216806.
[2] Zhong et al, PRL 116 (2016): 077201.
[3] Tsirkin et al, PRB 97 (2018): 035158.
[4] wannier-berri.org