A Candidate for the Quantum Spin Liquid Ground-State in the Shastry-Sutherland Lattice Material Yb₂Be₂GeO₇

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 SrCu₂(BO₃)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, Yb₂Be₂GeO₇, of the rare-earth melilite family RE₂Be₂GeO₇. We find, through SQUID magnetometry, powder neutron diffraction, specific heat capacity, and muon spin relaxation, that Yb₂Be₂GeO₇ lacks magnetic order and exhibits persistent spin dynamics to at least 17 mK. We propose the Shastry-Sutherland lattice material Yb₂Be₂GeO₇ as a candidate to host a quantum spin liquid ground-state.