We have studied the magnetic properties of clinoatacamite Cu2Cl(OH)3, the parent compound of the quantum spin liquid candidate herbertsmithite and a longstanding puzzle among frustrated quantum magnets. As we reveal using density-functional theory, clinoatacamite belongs to the class of distorted kagome antiferromagnets with the kagome plane being embedded into a low-symmetry crystal structure. By means of thermodynamic measurements, muon spin rotation/relaxation as well as neutron diffraction on single crystals, we find a complex sequence of phases/regions below 18.1 K in zero magnetic field. We propose this complexity in multicritical clinoatacamite to arise from the competition of antiferromagnetic ordering modes from the underconstrained manifold of modes, which can lead to a metamagnetic texture in zero magnetic field.
@article{arxiv.2601.21024,
title = {Competing Ordering Modes in the Distorted Quantum Kagome Material Clinoatacamite Cu$_2$Cl(OH)$_3$},
author = {L. Stödter and C. Kastner and H. O. Jeschke and M. Reehuis and K. Beauvois and B. Ouladdiaf and E. Chan and F. Yokaichiya and F. Bert and T. J. Hicken and J. A. Krieger and H. Luetkens and J. L. Allen and R. Feyerherm and M. Tovar and D. Menzel and A. U. B. Wolter and B. Büchner and K. C. Rule and F. J. Litterst and U. K. Rößler and S. Süllow},
journal= {arXiv preprint arXiv:2601.21024},
year = {2026}
}