Nano-scale collinear multi-Q states driven by higher-order interactions

Abstract

Complex magnetic order arises due to the competition of different interactions between the magnetic moments. Recently, there has been an increased interest in such states not only to unravel the fundamental physics involved, but also with regards to applications exploiting their unique interplay with moving electrons. Whereas it is the Dzyaloshinskii-Moriya interaction (DMI) that has attracted much attention because of its nature to induce non-collinear magnetic order including magnetic-field stabilized skyrmions, it is the frustration of exchange interactions that can drive magnetic order down to the nano-scale. On top of that, interactions between multiple spins can stabilize two-dimensional magnetic textures as zero-field ground states, known as multi-Q states. Here, we introduce a two-dimensional itinerant magnet with various competing atomic-scale magnetic phases. Using spin-polarized scanning tunneling microscopy we observe several zero-field uniaxial or hexagonal nano-scale magnetic states. First-principles calculations together with an atomistic spin model reveal that these states are stabilized by the interplay of frustrated exchange and higher-order interactions while the DMI is weak. Unexpectedly, it is found that not only non-collinear magnetic states arise, but that higher-order interactions can also lead to collinear nano-scale multi-Q states.

32 pages including methods and additional information, 6 figures and 5 additional figures

References in corpus (7)

• Nanometric square skyrmion lattice in a centrosymmetric tetragonal magnet
• Meron, skyrmion, and vortex crystals in centrosymmetric tetragonal magnets
• Zoology of multiple-Q spin textures in a centrosymmetric tetragonal magnet with itinerant electrons
• Magnetic structure of monatomic Fe chains on Re(0001): emergence of chiral multi-spin interactions
• Trends of higher-order exchange interactions in transition-metal trilayers
• Topological-chiral magnetic interactions in ultrathin films at surfaces
• Signatures of quartic asymmetric exchange in a class of two dimensional magnets

Cited by in corpus (8)

• Type II multiferroic order in two-dimensional transition metal halides from first principles spin-spiral calculations
• Antiferromagnetism in two-dimensional materials: progress and computational challenges
• Magnetic order in the computational 2D materials database (C2DB) from high throughput spin spiral calculations
• Checkerboard bubble lattice formed by octuple-period quadruple-$Q$ spin density waves
• Thermally-induced mimicry of quantum cluster excitations and implications for the magnetic transition in FePSe${}_3$
• Entropy-driven phase transition in a non-collinear antiferromagnet due to higher-order exchange interactions
• A new skyrmion topological transition driven by higher-order exchange interactions in Janus MnSeTe
• Frustration-induced degenerate spin state with up-up-down-down ordering in corner-connected Heisenberg square-plaquettes