A Candidate for the Quantum Spin Liquid Ground-State in the Shastry-Sutherland Lattice Material Yb${}_2$Be${}_2$GeO${}_7$

Abstract

The quasi-2D Shastry-Sutherland model has remained topical in the field of condensed matter physics for the last two decades, following the experimental realization of the model in the material SrCu${}_2$(BO${}_3$)${}_2$. Since then, research into the Shastry-Sutherland system has revealed more nuanced physics than initially predicted; recent theoretical works have even predicted a quantum spin liquid phase may exist. Herein, we report on a new Shastry-Sutherland lattice material, Yb${}_2$Be${}_2$GeO${}_7$, of the rare-earth melilite family RE${}_2$Be${}_2$GeO${}_7$. We find, through SQUID magnetometry, powder neutron diffraction, specific heat capacity, and muon spin relaxation, that Yb${}_2$Be${}_2$GeO${}_7$ lacks magnetic order and exhibits persistent spin dynamics to at least 17 mK. We propose the Shastry-Sutherland lattice material Yb${}_2$Be${}_2$GeO${}_7$ as a candidate to host a quantum spin liquid ground-state.

11 pages, 7 figures, 4 tables