Transverse order and longitudinal fluctuations in a near-Ising spin supersolid
Abstract
We investigate the polarization of the ordered moments and low-energy spin fluctuations in the spin supersolid state of the S = 1/2 triangular-lattice easy-axis antiferromagnet K2Co(SeO3)2 using neutron scattering. The supersolid order develops through successive BKT transitions: the longitudinal order appears at higher temperature, while the transverse component associated with the Bose-Einstein condensate emerges only below a lower-temperature transition accompanied by a change in the interlayer correlations. At the lowest measured temperature, the transverse ordered moment reaches only 11% of the longitudinal component. Moreover, the low-energy spin fluctuations are found to be predominantly longitudinal in character. These results provide direct evidence that the supersolid ground state survives even in the near-Ising regime and exhibits longitudinal low-energy dynamics, imposing stringent constraints on microscopic theories of triangular-lattice XXZ antiferromagnets.
Keywords
Cite
@article{arxiv.2607.13635,
title = {Transverse order and longitudinal fluctuations in a near-Ising spin supersolid},
author = {Mengze Zhu and V. Romerio and S. Raymond and N. Murai and S. Ohira-Kawamura and K. Yu. Povarov and S. A. Zvyagin and R. Sibille and Arianna Minelli and Z. Yan and S. Gvasaliya and A. Zheludev},
journal= {arXiv preprint arXiv:2607.13635},
year = {2026}
}