Ba3Yb2Zn5O11: A model system for anisotropic exchange on the breathing pyrochlore lattice

          @misc{ pirsa_PIRSA:17050092,
            doi = {10.48660/17050092},
            url = {https://pirsa.org/17050092},
            author = {Rau, Jeffrey},
            keywords = {Condensed Matter},
            language = {en},
            title = {Ba3Yb2Zn5O11: A model system for anisotropic exchange on the breathing pyrochlore lattice},
            publisher = {Perimeter Institute},
            year = {2017},
            month = {may},
            note = {PIRSA:17050092 see, \url{https://pirsa.org}}
          }
          

Abstract

In this talk we present a study of the “breathing” pyrochlore compound Ba3Yb2Zn5O11. Due to the nearly decoupled nature of its tetrahedral units, this compound serves as an ideal testbed for exploring the nature of anisotropic exchange in a theoretically and experimentally tractable rare-earth system. The relevant low-energy model of the Yb3+ tetrahedra is parametrized by four anisotropic exchange constants and is capable of reproducing the inelastic neutron scattering data, specific heat, and magnetic susceptibility with high fidelity. Using this model, we predict the appearance of an unusual non-Kramers octupolar paramagnet at low temperatures. We further speculate on possible collective, inter-tetrahedron physics of these non-Kramers doublets and discuss applications to about anisotropic exchange in other rare-earth magnets.