Chiral and Clock phases in Twisted Dipolar Clusters

Abstract

We study samples and a dipolar model of magnetic rods arranged on twisted polygonal clusters in terms of the twist angle. We find that the relative twist between polygons induces noncollinear chiral phases, ranging from flux vortex closure to hedgehog like radial configurations. Chirality, quantified in terms of a bond order parameter, is an emergent property that behaves here as an Ising variable. The chiral configurations of the systems can be understood in terms of chirality and clock index order parameters, whose evolution with twist occurs through discontinuous switching of the magnetic textures. Within a fixed Ising chiral sector, the clock index, rooted in the $C_N$ invariance of the polygons, distinguishes chiral textures that share chirality. As the twist increases, it continuously shifts the preferred relative clock phase, but the N-fold anisotropy only allows discrete orientations; the competition produces a tilted N-fold energy landscape whose global minimum hops discontinuously between clock sectors. As the number of sites in the polygon grows, the resulting response displays a nonlinear crossover from rigid, Ising-like behavior to an almost $\mathrm{U}(1)$-invariant regime, governed by a twist-induced suppression of the emergent $Z_N$ clock anisotropy. Guided by symmetry considerations and the outcomes of the numerical minimization, we developed a Landau phenomenological description that is compatible with both the Ising-type chirality and the $Z_N$ clock anisotropy.

11 pages, 5 figures

References in corpus (25)

• Discovery of intrinsic ferromagnetism in 2D van der Waals crystals
• Chiral spin-wave edge modes in dipolar magnetic thin films
• Commensurate-incommensurate phase transition in bilayer graphene
• Quantum field theory for the chiral clock transition in one spatial dimension
• Micromagnetics of anti-skyrmions in ultrathin films
• Statistically Locked-in Transport Through Periodic Potential Landscapes
• Chirality scenario of the spin-glass ordering
• Evidence for chiral supercurrent in quantum Hall Josephson junctions
• Spontaneous antiferromagnetic skyrmion/antiskyrmion lattice and spiral spin liquid states in the frustrated triangular lattice
• Tuning magnetic chirality by dipolar interactions
• Commensurate-incommensurate phase transition and a network of domain walls in bilayer graphene with a biaxially stretched layer
• Phase transitions in the ${\mathbb{Z}}_p$ and U(1) clock models
• Residual discrete symmetry of the five-state clock model
• Twirling and spontaneous symmetry breaking of domain wall networks in lattice-reconstructed heterostructures of 2D materials
• Energetics and Structure of Domain Wall Networks in Minimally Twisted Bilayer Graphene under Strain
• A hierarchy of multi-moment skyrmion phases in twisted magnetic bilayers
• Designing hysteresis with dipolar chains
• Low-field behavior of an XY pyrochlore antiferromagnet: emergent clock anisotropies
• Partition function zeros of the p-state clock model in the complex temperature plane
• Electrically tunable correlated domain wall network in twisted bilayer graphene
• Ferrochiral, antiferrochiral, and ferrichiral skyrmion crystals in an itinerant honeycomb magnet
• Intrinsic chiral field as vector potential of the magnetic current in the zig-zag lattice of magnetic dipoles
• Lattice sine-Gordon model
• Chiral magnetic phases in Moire bilayers of magnetic dipoles
• Magnetic Solitons due to interfacial chiral interactions