Orbital Magnetic Moment of Magnons

Abstract

In experiments and applications usually the spin magnetic moment of magnons is considered. In this Paper we identify an additional degree of freedom of magnons: an \emph{orbital} magnetic moment brought about by spin-orbit coupling.Our microscopic theory uncovers that spin magnetization ${\vec{M}}^{\mathrm{S}}$ and orbital magnetization ${\vec{M}}^{\mathrm{O}}$ are independent quantities. They are not necessarily collinear; thus, even when the total spin moment is compensated due to antiferromagnetism (${\vec{M}}^{\mathrm{S}}=\vec{0}$), ${\vec{M}}^{\mathrm{O}}$ may be nonzero. This scenario of orbital weak ferromagnetism is realized in paradigmatic kagome antiferromagnets with Dzyaloshinskii-Moriya interaction. We demonstrate that magnets exhibiting a magnonic orbital moment are omnipresent and propose transport experiments for probing it.

References in corpus (9)

• Spin Seebeck insulator
• Observation of the Magnon Hall Effect
• Theoretical prediction of rotating magnon wavepacket in ferromagnets
• Signature of magnon Nernst effect in an antiferromagnetic insulator
• Weak ferromagnetic order breaking the threefold rotational symmetry of the underlying kagomé lattice in CdCu${}_3$(OH)${}_6$(NO${}_3$)${}_2\cdot$H${}_2$O
• Spin wave spectrum of the quantum ferromagnet on the pyrochlore lattice Lu2V2O7
• Magnonic Analogue of Edelstein Effect in Antiferromagnetic Insulators
• Anisotropic magnetic excitations from single-chirality antiferromagnetic state in Ca-kapellasite
• Orbital Nernst Effect of Magnons

Cited by in corpus (23)

• Observation of the orbital Hall effect in a light metal Ti
• Orbitronics: Orbital Currents in Solids
• Catalog of Unconventional Magnons in Collinear Magnets
• Thermal Hall effect of magnons in collinear antiferromagnetic insulators: signatures of magnetic and topological phase transitions
• Evidence of Magnon-Mediated Orbital Magnetism in a Quasi-2D Topological Magnon Insulator
• Reversal of Orbital Hall Conductivity and Emergence of Tunable Topological Quantum States in Orbital Hall Insulator
• Topological Hybrids of Magnons and Magnon Bound Pairs
• Interface transparency to orbital current
• Nonvolatile Magnonics in Bilayer Magnetic Insulators
• Generation of twisted magnons via spin-to-orbital angular momentum conversion
• Intrinsic Nernst effect of the magnon orbital moment in a honeycomb ferromagnet
• Sign Changes in Heat, Spin, and Orbital Magnon Transport Coefficients in Kitaev Ferromagnets
• Type-II Dirac points and Dirac nodal loops on the magnons of square-hexagon-octagon lattice
• Orbital Edelstein effect of electronic itinerant orbital motion at edges
• Exact Results for the Orbital Angular Momentum of Magnons on Honeycomb Lattices
• Discovery of terahertz-frequency orbitally-coupled magnons in a kagome ferromagnet
• Tunable magnon band topology and magnon orbital Nernst effect in noncollinear antiferromagnets
• Electric polarization induced by magnons and magnon Nernst effects
• Chiral magnon in ferromagnetic chiral crystals
• Spin Nernst and thermal Hall effects of topological triplons in quantum dimer magnets on the maple-leaf and star lattices
• Proper Theory of Magnon Orbital Angular Momentum at Equilibrium
• Orbital Hall effect from orbital magnetic moments of Bloch states: the role of a new correction term
• Ferroelectric Switchable Topological Magnon Hall Effect in Type-I Multiferroics