Candidate for a quantum spin liquid ground state in the Shastry-Sutherland lattice material Yb2Be2GeO7

The quasi-two-dimensional 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.