Τίτλος:
Multiple Dirac nodes and symmetry protected Dirac nodal line in orthorhombic α-RhSi
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
Exotic multifold topological excitations have been predicted and were recently observed in transition metal silicides like β-RhSi. Herein, we report that interesting topological features of RhSi are also observed in its orthorhombic α phase, which displays multiple types of Dirac nodes very close to the Fermi level ÉF. We discuss the symmetry analysis, band connectivity along high-symmetry lines using group representations, band structure, the nature of the Dirac points and of a nodal line occurring near ÉF which is protected by the crystalline symmetry. The de Haas-van Alphen effect indicates a Fermi surface in agreement with the calculations. We find an elliptically shaped nodal line very close to ÉF around and near the S point on the ky-kz plane that results from the intersection of two upside-down Dirac cones. Both Dirac points of the participating Kramers degenerate bands are only 5 meV apart; hence, an accessible magnetic field might induce a crossing between the spin-up partner of the upper Dirac cone and the spin-down partner of the lower Dirac cone, possibly explaining the anomalies observed in the magnetic torque. α-RhSi is a unique system since all bands crossing ÉF emerge from Dirac nodes. © 2020 American Physical Society.
Συγγραφείς:
Mozaffari, S.
Aryal, N.
Schönemann, R.
Chen, K.-W.
Zheng, W.
McCandless, G.T.
Chan, J.Y.
Manousakis, E.
Balicas, L.
Περιοδικό:
Physical Review B
Εκδότης:
American Physical Society
Λέξεις-κλειδιά:
Silicides; Silicon; Topology; Transition metals, Crystalline symmetry; De Haas-van Alphen effect; Group representation; Magnetic torques; Symmetry analysis; Topological excitations; Topological features; Transition metal silicides, Rhodium compounds
DOI:
10.1103/PhysRevB.102.115131
