• DOI:10.21468/SCIPOSTPHYS.9.3.041
• Corpus ID: 218613626

Long-range magnetic order in the ${\tilde S}=1/2$ triangular lattice antiferromagnet KCeS$_2$

@article{Bastien2020LongrangeMO,
  title={Long-range magnetic order in the \$\{\tilde S\}=1/2\$ triangular lattice antiferromagnet KCeS\$\_2\$},
  author={G{\"a}el Bastien and B Rubrecht and Ellen M. Haeussler and Ph. Schlender and Ziba Zangeneh and Stas M. Avdoshenko and R. Sarkar and A. Alfonsov and Sven Luther and Y. A. Onykiienko and Helen C. Walker and H. Kuhne and Vadim Grinenko and Zurab Guguchia and Vladislav Kataev and H.-H. Klauss and Liviu Hozoi and Jeroen van den Brink and Dmytro S. Inosov and Bernd Buchner and Anja U. B. Wolter and Thomas Doert},
  journal={arXiv: Strongly Correlated Electrons},
  year={2020}
}

• G. Bastien, B. Rubrecht, +19 authors T. Doert
• Published 13 May 2020
• Physics
• arXiv: Strongly Correlated Electrons

Recently, several putative quantum spin liquid (QSL) states were discovered in ${\tilde S} = 1/2$ rare-earth based triangular-lattice antiferromagnets (TLAF) with the delafossite structure. A way to clarify the origin of the QSL state in these systems is to identify ways to tune them from the putative QSL state towards long-range magnetic order. Here, we introduce the Ce-based TLAF KCeS$_2$ and show via low-temperature specific heat and $\mu$SR investigations that it yields magnetic order below $T_{\mathrm N} = 0.38$ K despite the same delafossite structure. We identify a well separated ${\tilde S} = 1/2$ ground state for KCeS$_2$ from inelastic neutron scattering and embedded-cluster quantum chemical calculations. Magnetization and electron spin resonance measurements on single crystals indicate a strong easy-plane $g$~factor anisotropy, in agreement with the ab initio calculations. Finally, our specific-heat studies reveal an in-plane anisotropy of the magnetic field-temperature phase diagram which may indicate anisotropic magnetic interactions in KCeS$_2$.