Giant spatial anisotropy of magnon lifetime in altermagnets

Abstract

Altermagnets are a new class of magnetic materials with zero net magnetization (like antiferromagnets) but spin-split electronic bands (like ferromagnets) over a fraction of reciprocal space. As in antiferromagnets, magnons in altermagnets come in two flavours, that either add one or remove one unit of spin to the $S=0$ ground state. However, in altermagnets these two magnon modes are non-degenerate along some directions in reciprocal space. Here we show that the lifetime of altermagnetic magnons has a very strong dependence on both flavour and direction. Strikingly, coupling to Stoner modes leads to a complete suppression of magnon propagation along selected spatial directions. This giant anisotropy will impact electronic, spin, and energy transport properties and may be exploited in spintronic applications.

9 pages, 11 figures (including the appendices)

References in corpus (12)

• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Twisted Magnetic Van der Waals Bilayers: An Ideal Platform for Altermagnetism
• Two-dimensional altermagnets from high throughput computational screening: symmetry requirements, chiral magnons and spin-orbit effects
• Realizing Altermagnetism in Fermi-Hubbard Models with Ultracold Atoms
• Weak-Coupling Theory of Neutron Scattering as a Probe of Altermagnetism
• Antiferromagnetic magnon spintronic based on non-reciprocal and non-degenerated ultra-fast spin-waves in the canted antiferromagnet α-Fe2O3
• Spin pumping in an altermagnet/normal metal bilayer
• Magnon spectrum of altermagnets beyond linear spin wave theory: Magnon-magnon interactions via time-dependent matrix product states vs. atomistic spin dynamics
• Broken-symmetry magnetic phases in two-dimensional triangulene crystals
• Direct probing of a large spin-orbit coupling in the FeSe superconducting monolayer on STO: Evidence for nontrivial topological states
• Theory of spin-polarized high-resolution electron energy loss spectroscopy from nonmagnetic surfaces with a large spin-orbit coupling
• Composite antiferromagnetic and orbital order with altermagnetic properties at a cuprate/manganite interface

Cited by in corpus (4)

• Systematic Mapping of Altermagnetic Magnons by Resonant Inelastic X-Ray Circular Dichroism
• Magnons from time-dependent density-functional perturbation theory and nonempirical Hubbard functionals
• Quantum effects in the magnon spectrum of 2D altermagnets via continuous similarity transformations
• Theory of Angle Resolved Photoemission Spectroscopy of Altermagnetic Mott Insulators