Indirect chiral magnetic exchange through Dzyaloshinskii–Moriya-enhanced RKKY interactions in manganese oxide chains on Ir(100)

Abstract

Localized electron spins can couple magnetically via the Ruderman–Kittel–Kasuya–Yosida interaction even if their wave functions lack direct overlap. Theory predicts that spin–orbit scattering leads to a Dzyaloshinskii–Moriya type enhancement of this indirect exchange interaction, giving rise to chiral exchange terms. Here we present a combined spin-polarized scanning tunneling microscopy, angle-resolved photoemission, and density functional theory study of MnO 2 chains on Ir(100). Whereas we find antiferromagnetic Mn–Mn coupling along the chain, the inter-chain coupling across the non-magnetic Ir substrate turns out to be chiral with a 120° rotation between adjacent MnO 2 chains. Calculations reveal that the Dzyaloshinskii–Moriya interaction results in spin spirals with a periodicity in agreement with experiment. Our findings confirm the existence of indirect chiral magnetic exchange, potentially giving rise to exotic phenomena, such as chiral spin-liquid states in spin ice systems or the emergence of new quasiparticles.

Dirac magnons, nodal lines, and nodal plane in elemental gadolinium

“…Like on the honeycomb lattice [12], it is symmetry-allowed on the HCP lattice second nearest neighbor bonds. Although the superexchange mechanism considered by Moriya [69] may seem prima facie incompatible with the Ruderman-Kittel-Kasuya-Yosida (RKKY)-like magnetism in rare-earths like Gd [52], RKKY-mediated DM exchanges have, in fact, been discussed in other contexts [70][71][72], which leads us to speculate that weak DM exchanges may be possible also in spin-orbit-coupled rare-earths. A more concrete reason to consider DM exchange is that it may be relevant to other HCP ferromagnets, or to potential devices where the interfacial DM exchange can be strong due to breaking of inversion symmetry.…”

Nature of Interfacial Dzyaloshinskii-Moriya Interactions in Graphene/Co/Pt(111) Multilayer Heterostructures

“…Because of the broken inversion symmetry requirement, DMI is usually active at surfaces and interfaces, where it triggers complex chiral ordered spin structures at the nanoscale, such as cycloidal textures [6,7] and skyrmions [8][9][10], and introduces asymmetry in the displacement of domain walls [11]. The latter property has been exploited in synthetic magnets [12,13].…”

Investigation of structural, electronic and magnetic properties of breathing metal–organic framework MIL-47(Mn): a first principles approach

“…This dependency of electronic properties on the magnetic conguration makes the investigation of the spin-orbit coupling within this MOF of interest for future study. Recently, spin spirals have been observed in manganese oxide chains experimentally 65 and conrmed by theoretical methods. This behavior can also occur for the MIL-47(Mn) system due to presence of 1-D Mn-O chain.…”