Strain-induced dispersive Landau levels: Application in twisted honeycomb magnets

Abstract

Elastic strain is known to spatially modulate the wave-function overlap of the atoms on the lattice and can drastically alter the properties of the quasiparticles. For example, strain in Dirac matter can be interpreted as an elastic gauge field inducing Landau levels. We here propose a general method resolving the dispersion of the strain-induced Landau levels in two-dimensional Dirac materials, regardless of the particular space dependence of the applied strain. We illustrate such a method with the twist-induced magnon Landau levels in honeycomb quantum magnet nanoribbons. For ferromagnetic nanoribbons, dispersive Dirac-Landau levels are induced in the center of the magnon bands, while for antiferromagnetic nanoribbons, the twist results in dispersive equidistant Landau levels at the top of the magnon bands.