Large Berry curvature effects induced by extended nodal structures: Rational design strategy and high-throughput materials predictions

Abstract

Berry curvature can drastically modify the electron dynamics, thereby offering an effective pathway for electron manipulation and novel device applications. Compared to zero-dimensional nodal points in Weyl/Dirac semimetals, higher-dimensional extended nodal structures, such as nodal lines and nodal surfaces, are more likely to intersect the Fermi surface, leading to large Berry curvature effects without fine-tuning the chemical potential. In this work, we propose a strategy that utilizes straight nodal lines (SNLs) and flat nodal surfaces (FNSs) to design large Berry curvature effects, and we exhaustively tabulate SNLs and FNSs within the 1651 magnetic space groups (MSGs). We demonstrate that SNLs and FNSs can generate large Berry curvature widely distributed in the Brillouin zone. As an application, we identify 158 MSGs that host FNSs, SNLs, or both and allow for nonvanishing anomalous Hall conductivity (AHC). Based on these 158 MSGs, we screen materials from the MAGNDATA magnetic material database for high-throughput calculations, identifying 60 materials with AHC values exceeding $500\,\Omega^{-1}{\rm cm}^{-1}$. We select the candidate materials $\rm SrRuO_3$ and $\rm Ca_2NiOsO_6$ to demonstrate the contributions of FNSs and SNLs to one and two nonvanishing AHC components, respectively. We also investigate the tuning of AHC through symmetry breaking, outlining all possible symmetry-breaking pathways, and select the candidate material HoNi to demonstrate this approach by applying an external magnetic field. Additionally, we identify Berry curvature quadrupoles in the candidate materials, indicating that our strategy can be generalized to Berry curvature multipole effects. Our work will guide both the theoretical and experimental design of materials with large Berry curvature effects, with significant implications for a wide range of device applications.