paper

Altermagnetism-induced higher-order topological Dirac semimetals in two-dimensional nonsymmorphic systems

arXiv:2611.04347 · doi:10.1103/7dmx-h9h3

Abstract

We propose an altermagnetism-induced route to a two-dimensional higher-order topological Dirac semimetal in a trilayer nonsymmorphic Dirac system. Interlayer hybridization preserves the nonsymmorphic bulk Dirac crossings and generates helical edge states in the trilayer phase. Introducing outer-layer -wave altermagnetic order gaps the helical edge states, while only the symmetry-protected Dirac crossing at high-symmetry point remains gapless. The resulting phase hosts a surviving bulk Dirac point, gapped edge spectra, and corner states. An exact layer-space decomposition further reveals that these features arise from the coexistence of a gapless Dirac sector and a gapped topological sector. Our results establish altermagnetism as an effective mechanism for engineering higher-order topological Dirac semimetals in two-dimensional nonsymmorphic systems.

References in corpus (64)