Negative-vector-chirality 120∘ spin structure in the defect- and distortion-free quantum kagome antiferromagnet YCu3(OH)6Cl3

Zorko, A.; Pregelj, M.; Gomilšek, M.; Klanjšek, M.; Zaharko, O.; Sun, W.; Mi, J.-X.

Abstract

The magnetic ground state of the ideal quantum kagome antiferromagnet (QKA) has been a longstanding puzzle, mainly because perturbations to the nearest-neighbor isotropic Heisenberg Hamiltonian can lead to various fundamentally different ground states. Here we investigate a recently synthesized QKA representative YCu3(OH)6Cl3, where perturbations commonly present in real materials, like lattice distortion and intersite ion mixing, are absent. Nevertheless, this compound enters a long-range magnetically ordered state below TN = 15 K. Our powder neutron diffraction experiment reveals that its magnetic structure corresponds to a coplanar 120 state with negative vector spin chirality. The ordered magnetic moments are suppressed to 0.42(2)μB, which is consistent with the previously detected spin dynamics persisting to the lowest experimentally accessible temperatures. This indicates either a coexistence of magnetic order and disorder or the presence of strong quantum fluctuations in the ground state of YCu3(OH)6Cl3.

Citation

Zorko, A., Pregelj, M., Gomilšek, M., Klanjšek, M., Zaharko, O., Sun, W., & Mi, J.-X. (2019). Negative-vector-chirality 120∘ spin structure in the defect- and distortion-free quantum kagome antiferromagnet YCu3(OH)6Cl3. Physical Review B, 100(14), Article 144420. https://doi.org/10.1103/physrevb.100.144420

• Journal Article Type: Article
• Online Publication Date: Oct 14, 2019
• Publication Date: Oct 1, 2019
• Deposit Date: Oct 25, 2019
• Publicly Available Date: Oct 25, 2019
• Journal: Physical Review B
• Print ISSN: 2469-9950
• Electronic ISSN: 2469-9969
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 100
• Issue: 14
• Article Number: 144420
• DOI: https://doi.org/10.1103/physrevb.100.144420
• Public URL: https://durham-repository.worktribe.com/output/1286948