Lattice-Geometry Driven Hybrid Nodal Fermions in Topological Semimetals

Successful classification of topological electronic states based on the crystalline lattice symmetries led to the identification of many topological materials through high-throughput first-principles modeling. Such symmetry-to-topology characterizations, however, ignore the effects of various crystallographic or nanoscopic motifs and their associated wavefunction properties even though they are essential for describing the numbers, energy-momentum relations, and geometries of the nontrivial states. Here, we discuss how spatial arrangements of atoms dictate the nature of energy dispersions of topological states in materials [1]. Specifically, we focus on anisotropic lattice materials and demonstrate that the lattice geometry-driven effective mass anisotropies dictate the hybrid nodal-line states by considering transition metal tetraphosphides MP4 (M = Transition metal) as exemplary materials. We also discuss a general theory of incorporating orientation-dependent carrier effective masses as experimental fingerprints for determining energy dispersion in topological materials.<br/><br/>[1] B. Patra, R. Verma, S.-M. Huang, B. Singh, arXiv:2304.13086 (2023).