Abstract
Spontaneous Hall conductivity has recently been reported in the triangular lattice antiferromagnet Co1/3TaS2 under a zero magnetic field. This phenomenon originates from the distinctive noncoplanar triple-Q magnetic ground state, possessing uniform real-space Berry curvature characterized by scalar spin chirality. We investigated the physical properties of Co1/3TaS2 by judiciously controlling the composition, revealing a drastic change in its bulk properties, even by slight variations in cobalt composition, despite the same crystal structure. For 0.299≤x≤0.325, CoxTaS2 keeps all the characteristics of the ground state consistent with the previous studies - two antiferromagnetic phase transitions at TN1 and TN2 (<TN1), a large spontaneous Hall conductivity [σxy(H=0)], and a weak ferromagnetic moment along the c axis. However, samples with x≥0.330 exhibit distinct bulk properties, including the absence of both σxy(H=0) and the weak ferromagnetic moment. Our neutron diffraction data reveal that CoxTaS2 with x≥0.330 develops coplanar helical magnetic order with qm1=(1/3, 0, 0). This is entirely different from what has been seen in x≤0.325, explaining the observed composition dependence.
| Original language | English |
|---|---|
| Article number | L060403 |
| Journal | Physical Review B |
| Volume | 109 |
| Issue number | 6 |
| DOIs | |
| State | Published - Feb 1 2024 |
Funding
We acknowledge our numerous discussions with C. Batista, Y.-G. Kang, M. J. Han, H.-J. Noh, and K. H. Lee. This work was supported by the Samsung Science & Technology Foundation (Grant No. SSTF-BA2101-05). P.P. acknowledges support by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, Materials Science and Engineering Division. The neutron scattering experiment at the Japan Proton Accelerator Research Complex (J-PARC) was performed under the user program (Proposals No. 2021B0049 and No. 2023A0036). J.-G.P. was partly funded by the Leading Researcher Program of the National Research Foundation of Korea (Grant No. 2020R1A3B2079375). This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy (DOE). The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for U.S. government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan .