[행사/세미나] [Seminar] Anomalous Hall signatures of nonsymmorphic nodal lines in the doped chromium chalcospinel CuCr2Se4
- 물리학과
- 조회수2885
- 2022-04-19
고체전자구조계산 연구실에서 강원대학교 물리학과의 김흥식 교수님을 초청하여 아래와 같이 세미나를 개최합니다.
학과 구성원 여러분의 많은 참여를 부탁 드립니다.
오프라인으로 진행되는 세미나입니다.
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○ Topic: Anomalous Hall signatures of nonsymmorphic nodal lines in the doped chromium chalcospinel CuCr2Se4
○ Speaker: 김 흥 식 교수님 (강원대학교 물리학과)
○ Date/time: 2022. 5. 3. (Tue.) 4:00 PM
○ Place: Natural Science 1, Room No. 31317
○ Abstract: An emerging phase of matter among the class of topological materials is nodal line semimetals, possessing symmetry-protected one-dimensional gapless lines at (or close to) the Fermi level in k space. When the k dispersion of the nodal line is weak, van Hove singularities generated by the almost flat nodal lines may be prone to instabilities introduced by additional perturbations such as spin-orbit coupling or magnetism. Here, we study the Cr-based ferromagnetic chalcospinel compound CuCr2Se4 (CCS) via first-principles electronic structure methods and reveal the true origin of its dissipationless anomalous Hall conductivity, which was not well understood previously. We find that CCS hosts nodal lines protected by nonsymmorphic symmetries, located in the vicinity of Fermi level, and that such nodal lines are the origin of the previously observed distinct behavior of the anomalous Hall signature in the presence of electron doping. The splitting of the nodal line via spin-orbit coupling produces a large Berry curvature, which leads to a significant response in anomalous Hall conductivity. Upon electron doping via chemical substitution or gating, or rotation of magnetization via external magnetic field, noticeable change of anomalous Hall behavior occurs, which makes CCS a promising compound for low-energy spintronics applications.