The synthesis and characterization of a new Yb-based material Ba3Yb2Zn5O11 are reported. This material is identified as the first model system of a pseudospin-1/2 quantum antiferromagnet on "breathing" pyrochlore lattice characterized by an alternating array of small and large Yb tetrahedra. Despite dominant antiferromagnetic interactions J ~ 7 K, a large amount of magnetic entropy (25%) remains at 0.38 K, indicating that each small Yb tetrahedron forms a unique doubly degenerate singlet state. These results are well described by the Heisenberg pseudospin-1/2 single tetrahedron model.
@article{arxiv.1404.6439,
title = {Experimental Realization of a Quantum Breathing Pyrochlore Antiferromagnet},
author = {K. Kimura and S. Nakatsuji and T. Kimura},
journal= {arXiv preprint arXiv:1404.6439},
year = {2014}
}
Comments
11 pages, 4 figures, submitted to PRL; rejected and transferred to PRB