We report the experimental observation of a shift of the boundaries of the spinon continuum caused by a Fermi-liquid interaction of spinons in the spin-liquid S=1/2 chain-type antiferromagnet K₂CuSO₄Br₂. The parameter of spinon interaction, which determines the probability of backscattering, is found. In the pseudospin S=1/2 chain-type strongly anisotropic antiferromagnet Cs₂CoCl₄, a shift in the magnetic resonance frequency is detected during the crossover from the disordered spin regime to the state of correlated XXZ-type spin chains at a temperature above the emergence of long-range antiferromagnetic order. This resonance shift is explained on the basis of the spectrum of spin excitations in correlated XXZ chains and corresponds to theoretical simulation of the spectra of spinon-type magnetic fluctuations in XXZ chains [P. Laurell et al. Phys. Rev. Lett.127 037201 (2021)].

Keywords: spin chains, spinons, spin liquids, magnetic resonance, antiferromagnets, quantum magnets PACS: 75.10.Jm, 75.10.Pq, 75.40.Gb (all) DOI: 10.3367/UFNe.2024.12.039842 URL: https://ufn.ru/en/articles/2025/7/j/ 2-s2.0-105013768298 2025PhyU...68..728S Citation: Smirnov A I "Fermi liquid of spinons in quasi-one-dimensional antiferromagnets" Phys. Usp. 68 728–735 (2025) BibTexBibNote ® (generic)BibNote ® (RIS)MedlineRefWorks Received: 18th, December 2024, accepted: 18th, December 2024 Оригинал: Смирнов А И «Ферми-жидкость спинонов в квазиодномерных антиферромагнетиках» УФН 195 778–786 (2025); DOI: 10.3367/UFNr.2024.12.039842