Twist-induced magnon Landau levels in honeycomb magnets

Abstract

Lattice deformation resulting from 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. Here we elaborate that a twist lattice deformation in two-dimensional honeycomb quantum magnet nanoribbons is equivalent to an elastic gauge field giving rise to magnon Landau quantization. When the ground state is ferromagnetic, dispersive Dirac-Landau levels are induced in the center of magnon bands, while for antiferromagnetic nanoribbons, the twist results in dispersive equidistant Landau levels at the top of magnon bands. The dispersions for both types of Landau levels are derived in the framework of the band theory.