Multiple Dirac Nodes and Symmetry Protected Dirac Nodal Line in Orthorhombic $\alpha$-RhSi

Abstract

Owing to their chiral cubic structure, exotic multifold topological excitations have been predicted and recently observed in transition metal silicides like $\beta$-RhSi. Herein, we report that the topological character of RhSi is also observed in its orthorhombic $\alpha$-phase which displays multiple types of Dirac nodes very close to the Fermi level (${\epsilon }_F$) with the near absence of topologically trivial carriers. We discuss the symmetry analysis, band connectivity along high-symmetry lines using group representations, the band structure, and the nature of the Dirac points and nodal lines occurring near ${\epsilon }_F$. The de Haas-van Alphen effect (dHvA) indicates a Fermi surface in agreement with the calculations. We find an elliptically-shaped nodal line very close to ${\epsilon }_F$ around and near the $S$-point on the $k_y-k_z$ plane that results from the intersection of two upside-down Dirac cones. The two 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.

References in corpus (39)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Weyl and Dirac Semimetals in Three Dimensional Solids
• Optimized norm-conserving Vanderbilt pseudopotentials
• Discovery of a Three-dimensional Topological Dirac Semimetal, Na3Bi
• Topological nodal semimetals
• Topological quantum chemistry
• Ultrahigh mobility and giant magnetoresistance in the Dirac semimetal Cd${}_3$As${}_2$
• Beyond Dirac and Weyl fermions: Unconventional quasiparticles in conventional crystals
• Topological nodal line semimetals with and without spin-orbital coupling
• Dirac Cone Protected by Non-Symmorphic Symmetry and 3D Dirac Line Node in ZrSiS
• Topological nodal line semimetals
• Topological Semimetals
• Quantized circular photogalvanic effect in Weyl semimetals
• Topological classification of crystalline insulators through band structure combinatorics
• Quantum Oscillations from Surface Fermi-Arcs in Weyl and Dirac Semi-Metals
• Multiple types of topological fermions in transition metal silicides
• Large Fermi Arcs in Unconventional Weyl Semimetal RhSi
• Topological Semimetals Predicted from First-principles Calculations
• Transport evidence for Fermi-arc mediated chirality transfer in the Dirac semimetal Cd${}_3$As${}_2$
• Discovery of topological chiral crystals with helicoid arc states
• New classes of chiral topological nodes with non-contractible surface Fermi arcs in CoSi
• Experimental Observation of Three-Component 'New Fermions' in Topological Semimetal MoP
• Double Dirac Semimetals in Three Dimensions
• Weyl Metals
• Observation of Chiral Fermions with a Large Topological Charge and and Associated Fermi-Arc Surface States in CoSi
• Double crystallographic groups and their representations on the Bilbao Crystallographic Server
• Chiral Topological Semimetal with Multifold Band Crossings and Long Fermi arcs
• Semimetal and Topological Insulator in Perovskite Iridates
• Electronic Transport and quantum oscillation of Topological Semimetals
• Numerical extraction of de Haas - van Alphen frequencies from calculated band energies
• Chiral Optical Response of Multifold Fermions
• Co-existence of Weyl Fermion and Massless Triply Degenerate Nodal Points
• Dirac, Majorana and Weyl fermions
• Observation and control of maximal Chern numbers in a chiral topological semimetal
• Graph Theory Data for Topological Quantum Chemistry
• Band structure and unconventional electronic topology of CoSi
• Chiral anomaly and giant magnetochiral anisotropy in noncentrosymmetric Weyl semimetals
• Chiral fermion reversal in chiral crystals
• Origin of the butterfly magnetoresistance in a Dirac nodal-line system

Cited by in corpus (7)

• Universal sublinear resistivity in vanadium kagome materials hosting charge density waves
• Superconductivity and a van Hove singularity confined to the surface of a topological semimetal
• Shubnikov-de Haas and de Haas-van Alphen oscillation in Czochralski grown CoSi single crystal
• Anisotropic positive linear and sub-linear magnetoresistivity in the cubic type-II Dirac metal Pd${}_3$In${}_7$
• Electrical conductivity and screening effect of spin-1 chiral fermions scattered by charged impurities
• Band Curvature Effects on Quantum Transport of Spin-1 Chiral Fermion Systems
• Spin-to-charge conversion in orthorhombic RhSi topological semimetal crystalline thin films