Collinear and Non-Collinear Configurations in Classical Geometrically Frustrated Ring-Shaped Systems

M. Grajeka, T. Kopyciuka, W. Floreka, A. Marlewskib aFaculty of Physics, Adam Mickiewicz University in Poznań, Poland bInstitute of Mathematics, Poznań University of Technology, Poland

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Geometrically frustrated quantum spin systems, with competing antiferromagnetic couplings, show the Kahn degenerate frustration for some specific values of Heisenberg Hamiltonian parameters. It has been recently shown for rings with a defect bond and centered rings. In the case of classical counterparts of these systems, degenerated configurations with the lowest energy are present for the energy function parameter greater than a certain threshold. In these domains such configurations are planar but non-collinear with continuous changes of the net magnetic moment with respect to the Hamiltonian parameter. Outside these domains there is unique collinear ground state configuration (neglecting choice of the net magnetic moment direction). However, these collinear configurations are the same in both non-frustrated and geometrically frustrated domains. Numerically exact calculations for quantum systems strongly confirm that determined properties of their classical counterparts realize the classical limit s → ∞.

DOI: 10.12693/APhysPolA.133.417 PACS numbers: 75.10.Jm, 75.10.Hk, 75.50.Xx